Polycystic ovary syndrome (PCOS) is associated with impaired ovarian steroidogenesis and ovulation, which necessitates the development of effective ovulation inducers for PCOS. The aim of the study was to evaluate the effects of allosteric luteinizing hormone receptor agonist TP03 and human chorionic gonadotropin (hCG) on ovarian steroidogenesis, as well as ovulation in prepubertal female rats with dehydroepiandrosterone(DHEA)-induced PCOS. Taking into account differences in progesterone levels, cohorts with high (PCOS(H)) and low (PCOS(L)) progesterone were formed and treated with Follimag and Cetrotide. After 48 h, TP03 (25 mg/kg) or hCG (25 IU/rat) were injected, and hormone levels, gene expression, and ovarian morphology were assessed. The PCOS(H)-cohort exhibited irregular estrous cycles, ovarian cysts, and increased ovarian mass and estradiol levels, but the number of corpora lutea (CL) was maintained. In the PCOS(L)-cohort, ovarian weight was increased, and Star, Cyp11a1, and Adamts1 gene expression as well as the CL number were decreased. In both cohorts, TP03 and hCG increased progesterone levels and the expression of steroidogenesis (Star, Cyp11a1) and ovulation (Cox2, Adamts1, Egr1) genes, as well as inducing CL formation. Thus, TP03, like hCG, stimulates steroidogenesis and ovulation in PCOS-rats with different progesterone levels, which provides the first evidence of the effectiveness of allosteric LHR agonists as ovulation triggers in PCOS.

The approaches to correct thyroid deficiency include replacement therapy with thyroid hormones (THs), but such therapy causes a number of side effects. A possible alternative is thyroid-stimulating hormone (TSH) receptor activators, including allosteric agonists. The aim of this work was to study the effect of ethyl-2-(4-(4-(5-amino-6-(tert-butylcarbamoyl)-2-(methylthio)thieno[2,3-d]pyrimidin-4-yl)phenyl)-1H-1,2,3-triazol-1-yl) acetate (TPY3m), a TSH receptor allosteric agonist developed by us, on basal and thyroliberin (TRH)-stimulated TH levels and the hypothalamic-pituitary-thyroid (HPT) axis in male rats with high-fat diet/low-dose streptozotocin-induced type 2 diabetes mellitus (T2DM). Single and three-day administration of TPY3m (i.p., 20 mg/kg) was studied, and the effect of TPY3m on the HPT axis was compared with that of levothyroxine. TPY3m increased TH levels when administered to both healthy and diabetic rats, normalizing thyroxine and triiodothyronine levels in T2DM and, unlike levothyroxine, without negatively affecting TSH levels or the expression of hypothalamic and pituitary genes responsible for TSH production. TPY3m pretreatment preserved the stimulatory effects of TRH on TH levels and thyroid gene expression. This indicates the absence of competition between TPY3m and endogenous TSH for TSH receptor activation and is supported by our in vitro results on TPY3m- and TSH-stimulated adenylate cyclase activity in rat thyroid membranes. Morphological analysis of thyroid glands in diabetic rats after three-day TPY3m administration shows an increase in its functional activity without destructive changes. To summarize, TPY3m, with the activity of a partial allosteric agonist of the TSH receptor, was created as a prototype of drugs to correct thyroid insufficiency in T2DM.

The inherent benefits of Raman spectroscopy make it a suitable tool for the analysis of complex biological objects. Detection and imaging of mammalian cells is one of its development areas. Plasmonic tags endowed with alkyne reporter intended for bioimaging by surface-enhanced Raman scattering in the silent region are presented. Gold nanorods with covalently conjugated 4-aminotolane were obtained using dithiobis (succinimidyl propionate) and characterized by UV-Vis absorbance, transmission electron microscopy, and dynamic light scattering. Verification of surface amide bonds formation was performed with attenuated total reflectance and X-ray photoelectron spectroscopy. Surface-enhanced Raman scattering spectra of the tags were registered in various media and compared with a feedback from the similar system obtained through non-specific adsorption of 4-aminotolane on gold nanorods. Cytotoxicity of Raman reporter itself and its conjugates with gold nanorods were verified on HeLa cell line. Spectral mapping and scanning electron microscopy revealed the localized intracellular accumulation of the tags. The challenge associated with reduced imaging area due to formation of the tags aggregates inside the cells is pointed out.

Objective: Despite the fact that hypothyroid conditions, including autoimmune thyroiditis, are widespread pathologies, the possibilities of their pharmacological correction are very limited, including, mainly, the replacement therapy with thyroid hormones (THs). However, such therapy is characterized by many side effects, in connection with which alternative ways of stimulating the thyroid system are being developed, including the use of low-molecular regulators. Their target is allosteric sites located in the transmembrane domain of the thyroid-stimulating hormone (TSH) receptor. The aim of the study was the synthesis and physicochemical characterization of a new compound TPY7, methyl 2-(4-(4-(5-amino-6-(tert-butylcarbamoyl)-2-(methylthio)thieno[2,3-d]pyrimidin-4-yl)phenyl)-1H-1,2,3-triazol-1-yl) acetate, a methylated analogue of TPY3m, a TSH receptor agonist developed by us earlier, and to study the ability of TPY7 (in comparison with TPY3m) to influence the levels of total (tT4) and free (fT4) thyroxine and free triiodothyronine (fT3) and the expression of thyroglobulin (Tg), thyroid peroxidase (Tpo), and type 2 deiodinase (Dio2) genes in the thyroid gland of rats with one- and five-day administration, including stimulation of the thyroid system with thyroliberin (TRH). Material and methods: Blood levels of TG and TSH were assessed using enzyme immunoassay. Expression of genes responsible for TG synthesis was measured using real-time PCR. Results and discussion: When administered to rats, TPY7 dose-dependently increased the production of tT4 and fT3, and at a dose of 15 mg/kg (i.p.) also increased the expression of the Tpo and Dio2 genes responsible for the synthesis and conversion of THs. Its stimulating effect was maintained after five days of administration, indicating the absence of significant desensitization of the TSH receptor and its signaling cascades with long-term exposure to TPY7. In terms of the effectiveness of the stimulating effect on the thyroid system, TPY7 was inferior to TPY3m, although to a small extent. At the same time, unlike TPY3m, TPY7 potentiated the effects of TRH, increasing its stimulating effect on the levels of tT4 and fT3 in the blood and on the expression of the Dio2 gene in the thyroid gland. Conclusions: Thus, we have developed for the first time an active in vivo allosteric ligand of the TSH receptor with the activity of a partial agonist and a positive allosteric modulator (ago-PAM). TPY7 is a prototype for the creation of drugs that can be used to treat hypothyroidism and as stimulators of radioactive iodine uptake by thyrocytes in thyroid cancer radiotherapy.

Graves' disease is caused by overactivation of the thyroid-stimulating hormone receptor (TSHR). One approach for its treatment may be the use of negative allosteric modulators (NAM) of TSHR, which normalize TSHR activity and do not cause thyroid hormone (TH) deficiency. The aim of the work was to study the effect of a new compound 5-amino-4-(4-bromophenyl)-2-(methylthio)thieno[2,3-d]pyrimidine-6-carboxylic acid N-tert-butylamide (TPY4) on the basal and TSH-stimulated TH production in cultured FRTL-5 thyrocytes and on basal and thyrotropin-releasing hormone (TRH)-stimulated TH levels in the blood of rats. TPY4 stimulated TH production by thyrocytes and increased TH levels when administered intraperitoneally and orally in rats. It also decreased the TSH-stimulated TH production in thyrocytes and the TRH-stimulated TH levels in rats. Thus, TPY4 is the first known allosteric regulator of TSHR, combining the properties of NAM and a partial agonist, and can be considered as a prototype of drugs for the treatment of Graves' disease.

In experiments on rats, we studied the effect of 5-day intraperitoneal (15 mg/kg/day) and oral (40 mg/kg/day) administration of compound TPY3m, a stimulator of the production of thyroid hormones by the thyroid gland developed by us, on the blood levels of thyroxine, triiodothyronine, and thyroid-stimulating hormone and on morphology of the thyroid gland. With both routes of administration, TPY3m caused a sustained moderate elevation of thyroid hormones, mainly thyroxine, with little effect on the level of thyroid-stimulating hormone. TPY3m did not reduce the stimulating effect of thyroliberin on the levels of thyroid hormones and had no damaging effect on the thyroid gland. During long-term administration, compound TPY3m stimulates the production of thyroid hormones without weakening the activity of the thyroid axis. Thus, TPY3m is a prototype of drugs for correcting thyroid hormone deficiency.

Autoimmune hyperthyroidism (Graves’ disease), which is caused by stimulating autoantibodies to the thyroid-stimulating hormone receptor (TSHR), and thyroid tumors, caused by a constitutively increased activity of this receptor, are widespread and have a poor prognosis. The drugs used to treat them are low effective and have many side effects. One of the therapeutic approaches to these thyroid diseases may be the use of TSH receptor allosteric regulators with an activity of inverse agonists. This work was aimed to study the effects of the compound TP48, previously synthesized in our laboratory, and a newly synthesized compound TPY5, with both of them referring to thieno[2,3-d]-pyrimidines, on basal and thyrotropin-releasing hormone (TRH)-stimulated levels of thyroid hormones (THs) in the rat blood and on the expression of genes responsible for TH synthesis in the rat thyroid gland. TP48 and TPY5 effectiveness was studied upon both intraperitoneal (20 mg/kg) and peroral (40 mg/kg) administration. Using ELISA, blood levels of free (fT4) and total (tT4) thyroxine, as well as free (fT3) and total (tT3) triiodothyronine, were assessed, including during stimulation with intranasal TRH (300 µg/kg). Gene expression for thyroid peroxidase (Tpo), thyroglobulin (Tg), Na+/I– symporter (Nis), type 2 deiodinase (Dio2), and TSH receptor (Tshr) in the thyroid gland was assessed by PCR. TPY5, administered via both routes, reduced both basal and TRH-stimulated plasma TH levels, while TP48 suppressed TH production only after intraperitoneal administration. Peroral TPY5 significantly reduced basal Tpo expression, as well as TRH-stimulated Tg and Dio2 expression. Intraperitoneal TP48 reduced only TRH-stimulated Tg and Dio2 expression. Quite surprisingly, peroral TPY5 and intraperitoneal TP48 reduced basal Tshr expression but did not prevent its inhibition by TRH. Thus, the novel compound TPY5 exhibits the activity of a TSH receptor inverse agonist and is effective when administered perorally, which is more in demand in medicine; it can be considered as a prototype of drugs to treat autoimmune hyperthyroidism and thyroid tumors.

Background: Luteinizing hormone (LH) and human chorionic gonadotropin (hCG) preparations are widely used in medicine to correct reproductive disorders, but are characterized by many side effects. In this regard, low-molecular-weight allosteric agonists of the LH receptor (LHR) are being developed, the most active of which are thieno[2,3-d]-pyrimidine derivatives (TPs). Aim: To study the stimulating effects of the compound TP03, developed by us, on the activity of the membrane-bound adenylate cyclase (AC) in vitro and on testicular and ovarian steroidogenesis in vivo in comparison with those of Org43553, the “gold” standard of low-molecular-weight LHR agonists. Materials and methods: The effects of TP03 and Org43553 (10-8–10-3 M) on basal and hCG-stimulated (10-9 M) AC activity in membrane fractions isolated from rat testes and ovaries were assessed in vitro using [α-32P]-ATP. The effects of TP03 and Org43553 (in two doses – 10 and 20 mg/kg, i.p.) on blood testosterone levels in male rats and on blood progesterone levels in immature female rats pre-stimulated with Follimag® were assessed in vivo, as well as the effect of co-administration of TP03 or Org43553 (10 mg/kg, i.p.) with hCG (10 IU/rat, s.c.) on testosterone levels in male rats. Testosterone and progesterone levels were determined using enzyme immunoassay. Results: Compound TP03 was comparable to Org43553 in its ability to stimulate AC in rat testicular and ovarian membranes. When administered to male rats, TP03 dose-dependently stimulated testosterone production, and when administered to immature female rats, it increased their progesterone levels, not inferior to Org43553 in these parameters. When relatively low doses of TP03 and hCG were administered together to male rats, additivity of their stimulating effects on testosterone levels was observed, and the additivity was more pronounced than in the case of a combination of Org43553 and hCG. Conclusions: The compound TP03 we developed is comparable in its ability to stimulate testicular and ovarian steroidogenesis to the compound Org43553, and along with this, it demonstrates additivity when used in combination with hCG, which indicates the prospects for its use to increase the effectiveness of gonadotropin therapy.

BACKGROUND: Gonadotropin preparations, particularly human chorionic gonadotropin (hCG), are commonly used to induce ovulation and treat reproductive disorders in women, albeit with associated side effects. Low-molecular-weight allosteric agonists of the luteinizing hormone receptor (LHR), such as thieno[2,3-d]pyrimidine derivatives, offer a potential alternative. AIM: This study aims to compare the effects of thieno[2,3-d]pyrimidine TP03 and hCG on ovarian weight, corpus luteum formation, and plasma levels of estradiol, progesterone, and luteinizing hormone in immature female rats pre-treated with Follimag®. It also examines their impact on ovarian gene expression related to LHR and steroidogenesis. MATERIALS AND METHODS: TP03 and hCG were administered 48 h after the Follimag® injection at a dose of 20 mg/kg (i.p.) and 15 IU/rat (s.c.), respectively. Parameters were assessed at 1, 2, 4, 8, 16, and 24 h after TP03 and hCG administration. Plasma hormone levels were measured via ELISA, and ovarian gene expression was analyzed using real-time PCR. RESULTS: TP03 increased ovarian weight, progesterone levels in the blood, and expression of steroidogenic genes encoding the cholesterol-transporting protein StAR and the cytochromes CYP11A1 and CYP17A1. TP03 also stimulated corpus luteum formation (16–24 h after treatment). The temporal dynamics of its stimulating effects were similar to those of hCG, although their magnitude was slightly inferior to those of gonadotropin. TP03-induced decrease in blood estradiol levels and aromatase gene expression in the ovaries was also more moderate. Unlike hCG, which suppressed LHR gene expression 8 h after treatment, TP03 maintained a high LHR gene expression, preserving ovarian sensitivity to endogenous luteinizing hormone. CONCLUSIONS: TP03 exhibits potential as an ovulation inducer with milder stimulating effects on ovarian steroidogenesis than hCG, which reduces the risks of developing ovarian hyperstimulation syndrome and resistance to gonadotropins.

abstract-Surface-enhanced Raman scattering is characterized by high specificity, spatial resolution and signal-to-noise ratio which make it attractive for bioimaging purposes. Alkynes have a Raman signal in the region of $2050-2300 \mathrm{~cm}^{-1}$, which is convenient for optical tags tracking due to the absence of signals from cellular components. The use of alkynes in combination with plasmonic materials opens up the possibility of multifunctional medical diagnostic agents. In this work, the tags based on gold nanorods functionalized with 4 -aminotolan via covalent conjugation are developed for alkyne-targeted bioimaging and photothermal therapy.

This study presents the synthesis of N-alkynylated acyclic diaminocarbene (ADC) complexes of palladium(II) and platinum(II) and their intramolecular cyclization via trans-chlorometalation. The reactions of propargylamines with bis-isocyanide complexes of Pd(II) and Pt(II) produced the desired ADC complexes in good yields. The NH,NH-diaminocarbene complexes were unstable in solution and underwent intramolecular cyclization into chlorometalated products. These findings provide a novel route to stable N-alkynylated ADC complexes with potential applications in catalysis and medicinal chemistry. The complexes synthesized exhibit promising structural and reactive properties suitable for further exploration.

After the appearance of the green chemistry concept, which was introduced in the chemistry vocabulary in the early 1990s, its main statements have been continuously developed and modified. Currently, there are 10–12 cornerstones that should form the basis for an ideal chemical process. This review analyzes the accumulated experience and achievements towards the design of chemical products and processes that reduce or eliminate the use or generation of hazardous substances. The review presents the views of leading Russian scientists specializing in various fields of this subject, including homogeneous and heterogeneous catalysis, fine and basic organic synthesis, electrochemistry, polymer chemistry, chemistry based on bio-renewable feedstocks and chemistry of energetic compounds and materials. A new approach to the quantitative evaluation of the environmental friendliness of processes developed by Russian authors is described. The bibliography includes 1761.

BACKGROUND: In men, obesity is accompanied by a complex of metabolic and hormonal disorders, which leads to androgen deficiency and impaired spermatogenesis. Antidiabetic drugs, including metformin (MF), and luteinizing hormone receptor (LHR) agonists, which activate testicular steroidogenesis, can be used to correct reproductive dysfunctions. However, in diet-induced obesity (DIO), their effectiveness and mechanisms of action are poorly understood.AIM: In men, obesity is accompanied by a complex of metabolic and hormonal disorders, which leads to androgen deficiency and impaired spermatogenesis. Antidiabetic drugs, including metformin (MF), and luteinizing hormone receptor (LHR) agonists, which activate testicular steroidogenesis, can be used to correct reproductive dysfunctions. However, in dietinduced obesity (DIO), their effectiveness and mechanisms of action are poorly understood.MATERIALS AND METHODS: Obesity in male Wistar rats was induced by a 23-week diet enriched with saturated fats. MF treatment was carried out for 5 weeks at a dose of 120 mg/kg/day (orally), and the treatment with hCG and TP03 was carried out for 5 days at daily doses of 20 IU/rat (s.c.) and 15 mg/kg (i.p.), respectively. Using microscopy and histochemical analysis, the number and motility of spermatozoa (SP), the number of their defective forms and the morphology of the seminiferous tubules were assessed, and the levels of testosterone and other hormones in the blood were measured using ELISA.RESULTS: MF, hCG, and TP03 to varying degrees increased the number of SP and the proportion of their mobile forms, including those with forward movement, which were reduced in DIO rats, and also normalized the thickness of the epithelium of the seminiferous tubules and the number of spermatogonia and pachytene spermatocytes in them, but did not reduced the proportion of defective forms of SP, increased in DIO. In the case of MF, this was associated with the drug-induced normalization of body weight, glucose tolerance, and the insulin and leptin levels in DIO rats. The positive effect of hCG and TP03 on spermatogenesis was due to their stimulating effect on testosterone production.CONCLUSION: The use of long-term MF therapy and short-term courses of LHR-agonists normalizes impaired spermatogenesis in DIO, which indicates the prospects for their use to improve male fertility in obesity, and in the case of MF therapy, normalization of the metabolic and hormonal status is of great importance, while in the case of LHR-agonists the most important factor is their steroidogenic effect.

Dual inhibitors of protein phosphotyrosine phosphatase 1B (PTP1B)/T-cell protein phosphotyrosine phosphatase (TC-PTP) based on the 3-(hydroxymethyl)-4-oxo-1,4-dihydrocinnoline scaffold have been identified. Their dual affinity to both enzymes has been thoroughly corroborated by in silico modeling experiments. The compounds have been profiled in vivo for their effects on body weight and food intake in obese rats. Likewise, the effects of the compounds on glucose tolerance, insulin resistance, as well as insulin and leptin levels, have been evaluated. In addition, the effects on PTP1B, TC-PTP, and Src homology region 2 domain-containing phosphatase-1 (SHP1), as well as the insulin and leptin receptors gene expressions, have been assessed. In obese male Wistar rats, a five-day administration of all studied compounds led to a decrease in body weight and food intake, improved glucose tolerance, attenuated hyperinsulinemia, hyperleptinemia and insulin resistance, and also compensatory increased expression of the PTP1B and TC-PTP genes in the liver. The highest activity was demonstrated by 6-Chloro-3-(hydroxymethyl)cinnolin-4(1H)-one (compound 3) and 6-Bromo-3-(hydroxymethyl)cinnolin-4(1H)-one (compound 4) with mixed PTP1B/TC-PTP inhibitory activity. Taken together, these data shed light on the pharmacological implications of PTP1B/TC-PTP dual inhibition, and on the promise of using mixed PTP1B/TC-PTP inhibitors to correct metabolic disorders.

The regioselectivity of the Richter cyclization for a series of 4-halo-2-[(3,4,5 trimethoxyphenyl)ethynyl]anilines has been studied to obtain trimethoxybenzoyl-1H-indazoles, heteroanalogs of combretastatin. In aqueous acetonitrile, cinnolin-4(1H)-ones, which are products of 6-endo-dig cyclization, are formed along with 1H-indazoles, products of 5-exo-dig cyclization. In a DMSO:H2O mixture, 3-aroyl-1H-indazoles are formed exclusively. In the case of 2-[(4-methoxyphenyl)ethynyl]-4-haloanilines, the 5-exo-dig cyclization proceeds independently on the used solvent. Among the prepared trimethoxy-benzoyl-1H-indazoles, the 5-chloro-substituted indazole showed the highest cytotoxicity, while the fluoro-substituted indazole exhibited no severe cytotoxicity.

In clinical practice, ovarian steroidogenesis is stimulated and ovulation is induced using such gonadotropin preparations as human chorionic gonadotropin (hCG) and luteinizing hormone (LH) which, however, have a number of side effects, including a reduction in ovarian sensitivity to endogenous LH and ovarian hyperstimulation syndrome. An alternative to hCG and LH could be allosteric LH/hCG receptor agonists, including the thieno[2,3-d]-pyrimidine derivative TP03 developed in our laboratory. This work was aimed to study the effect of TP03 (40 µg/kg, i.p.) versus hCG (30 IU/rat, s.c.) on ovarian steroidogenesis in mature female rats in the late proestrus phase, including those treated with the gonadotropin releasing hormone (GnRH) antagonist Orgalutran (100 µg/kg, s.c., 3 h before TP03 or hCG administration). Estradiol, progesterone and LH levels were measured in the blood, while expression levels of the steroidogenesis-related genes Star, Cyp11a1, Hsd3b, Cyp17a1, Hsd17b, Cyp19a1 and LH/hCG receptor gene Lhcgr were assessed in the ovaries. Three hours after administration, TP03 and hCG increased blood progesterone levels and stimulated the expression of genes encoding the cholesterol-transporting protein StAR, cytochrome P450c17, and aromatase (cytochrome P450c19), with these effects detected both in control rats with normal LH levels and in Orgalutran-treated rats with reduced LH levels. The effects of TP03 were comparable to those of hCG, but in contrast to hCG, TP03 did not reduce the activity of the hypothalamic–pituitary–gonadal axis, as indicated by the lack of its influence on blood LH levels and ovarian expression of LH/hCG receptors. Our data suggest the ability of TP03 to effectively stimulate ovarian steroidogenesis, as well as good prospects for the development of TP03-based drugs for controlled ovulation induction.

Gonadotropins, including human chorionic gonadotropin (hCG), are used to induce ovulation, but they have a number of side effects, including ovarian hyperstimulation syndrome (OHSS). A possible alternative is allosteric luteinizing hormone (LH)/hCG receptor agonists, including the compound TP4/2 we developed, which remains active when administered orally. The aim was to study the effectiveness of TP4/2 (orally, 40 mg/kg) as an ovulation inducer in FSH-stimulated immature female rats, compared with hCG (s.c., 15 IU/rat). TP4/2 stimulated progesterone production and corpus luteum formation; time-dependently increased the ovarian expression of steroidogenic genes (Star, Cyp11a1, Cyp17a1) and genes involved in ovulation regulation (Adamts-1, Cox-2, Egr-1, Mt-1); and increased the content of metalloproteinase ADAMTS-1 in the ovaries. These effects were similar to those of hCG, although in some cases they were less pronounced. TP4/2, in contrast to hCG, maintained normal LH levels and increased the ovarian expression of the LH/hCG receptor gene, indicating preservation of ovarian sensitivity to LH, and did not cause a sustained increase in expression of vascular endothelial growth factor-A involved in OHSS. Thus, TP4/2 is an effective ovulation inducer that, unlike hCG, has a lower risk of OHSS and ovarian LH resistance due to its moderate stimulating effect on steroidogenesis.

Men with obesity demonstrate not only various metabolic disorders and insulin resistance, but also reduced testosterone levels and reproductive system dysfunctions. Although one of the ways for pharmacological correction of these abnormalities may be the use of luteinizing hormone receptor (LHR) agonists and antidiabetic drugs (specifically, metformin, MF), the mechanisms of their effects on the hypothalamic–pituitary–gonadal axis have not been sufficiently investigated. The aim of this work was to study the effects of long-term MF therapy (5 weeks, 120 mg/kg) and five-day treatment with LHR agonists, such as human chorionic gonadotropin (hCG, 20 IU/rat/day, s.c.) and allosteric agonist TP03 (15 mg/kg/day, i.p.), on blood testosterone levels and the expression of testicular and pituitary genes in male Wistar rats with long-term diet-induced obesity (DIO). TP03 moderately stimulated testosterone production in male rats with DIO without having an inhibitory effect on testicular LHR expression and only insignificantly reducing the pituitary expression of the LH β-subunit gene. After a single TP03 administration to DIO rats, its steroidogenic effect was comparable to that in the control group, but after a five-day administration, it was significantly inferior to it. In DIO rats, the steroidogenic effect of hCG after a single administration was lower than that in the control but comparable to that after a five-day administration, significantly exceeding the corresponding effects of TP03. Unlike TP03, hCG significantly reduced testicular LHR expression and more pronouncedly inhibited pituitary LH expression. MF treatment restored the androgenic status without significantly affecting the testicular expression of steroidogenic genes. In MF-treated groups, there was no increase in the steroidogenic effects of both LHR agonists. The results suggest the prospects for the use of TP03 and hCG to stimulate testicular steroidogenesis and increase the effectiveness of MF therapy in order to normalize testosterone production in DIO, which can be used to correct reproductive disorders in obesity. At the same time, a co-administration of MF and LHR agonists in DIO appears to be inappropriate.

In obesity, the insulin and leptin pathways in the brain and peripheral tissues are attenuated. In the brain, one of the reasons for this is the impaired transport of insulin and leptin across the blood–brain barrier (BBB), as indicated by changes in the ratio of their concentrations in the blood flow and different brain structures. However, neither these changes under obesity nor the effect of pharmacological agents on them are almost unstudied. The aim of the work was to assess insulin and leptin levels in the brain structures (hypothalamus, cerebellum) and their correlation with those in the blood of male rats with obesity caused by a long-term combined high-calorie diet, as well as to study the effect of a four-week treatment of obese rats with metformin (200 mg/kg/day), bromocriptine (0.6 mg/rat/day), intranasal insulin (I-I) (0.5 IU/rat/day), as well as their two-week treatment with PI4, a protein phosphotyrosine phosphatase 1B (PTP1B) inhibitor (10 mg/kg/day), on these parameters. It was shown that in obesity accompanied by with hyperinsulinemia and hyperleptinemia, insulin and leptin transport to the hypothalamus and cerebellum across the BBB is attenuated, leading to a significant increase in concentration ratios of these hormones in the blood and brain structures. Metformin treatment not only normalized metabolic parameters and sensitivity to insulin and leptin, but also completely restored their levels in the brain structures. Bromocriptine/I-I treatment was less effective. PI4 treatment of obese rats caused a significant loss in their body and adipose tissue weight, reduced their food intake, improved the metabolic parameters, and increased insulin and leptin sensitivity. The PTP1B inhibitor PI4 also restored the ratio of insulin and leptin concentrations in the blood and brain structures, but not due to an increase in their brain levels, as with metformin, but as a result of a significant decrease in blood hormone concentrations. Our data indicate that the treatment with drugs having varied chemical structure and mechanisms of action but sharing the ability to improve metabolic and hormonal parameters in obesity leads to normalization of insulin and leptin ratios at the periphery and in the CNS, thus restoring insulin and leptin signaling in the hypothalamus and other brain regions, as well as central insulin- and leptin-mediated regulation of metabolic processes at the periphery.