Separation flowsheets for three-, four-, and five-component mixtures are considered. Graphs analysis of the arrangement of feed-composition regions is performed to find the optimum separation flowsheet.

Experiments on primary cultures of human pituitary adenoma cells producing growth hormone (GH) or GH and prolactin showed that similarly to GH-releasing hormone (GHRH) synthetic hexapeptide GH-releasing peptide-2 (GHRP) directly enhance secretion of GH but not of prolactin by human pituitary cells. The effect of various doses of GHRP and GHRH applied in combination was additive or slightly synergistic in nature. Somatostatin inhibits secretion of GH induced by GHRP, GHRH, or their combination. A dissociation is found between the inhibitory effects of somatostatin on basal and stimulated GH secretion.

Somatoliberin stimulates secretion of growth hormone and has no effect on secretion of prolactin in primary cultures of hypophyseal adenoma cells obtained from acromegalic patients. A short-term contact of the cells with somatostatin inhibits secretion of growth hormone, while a long-term contact with this hormone inhibits prolactin production. Somatoliberin abolishes the inhibitory effect of somatostatin on the growth hormone secretion and at high concentrations stimulates it.

Antibodies to adeno-pituitary cell surface antigen (PCSA) were studied in 40 untreated children with idiopathic growth hormone (GH) deficiency to elucidate the role of autoimmune disorders in the pathogenesis of GH deficiency. Antibodies to rat PCSA were assayed by ELISA. PCSA was detected in 15% of patients with GH deficiency, in contrast to that in healthy children and children with autoimmune thyroid diseases. The authors consider that in some cases GH deficiency may be caused by autoimmune hypophysitis. A family study revealed PCSA in 25% of mothers of patients with GH deficiency. In a population of healthy women PCSA was detected in 5.7% cases. Hence, a hereditary background of autoimmune abnormality cannot be completely ruled out.

In experiments with NB2 rat lymphoma cells culture sensitive to lactogenic hormones the mitogenic activity of high molecular weight (> OOK) immunoreactive prolactin, found in substantial quantities in serum of certain hyperprolactinemic women, as compared to the activity of serum low molecular weight (23K) form, was studied. It was established that the ratio of immunoreactive to biologically active prolactin content in serums in cases of low molecular weight form predominance is close to 1,0 whereas in case of predominant content of high molecular weight form it is substantially higher (1.5-2.3), apparently because of low biological activity of high molecular weight form. Direct comparison of mitogenic effects of equivalent quantities of serum immunoreactive prolactin forms with high and low molecular weight, separated by gel-filtration, confirmed low biological activity of high molecular weight form. Monoclonal antibodies to prolactin completely suppressed mitogenic activity of low molecular weight form and only partially--high molecular weight one. The data obtained indicate that high and low molecular weight forms of human serum immunoreactive prolactin differ in their biochemical and functional characteristics. Therefore their ratio in the circulating blood can substantially affect the clinical manifestations of hyperprolactinemia.

Antibodies to adeno-pituitary cell surface antigen (PCSA) were studied in 40 untreated children with idiopathic growth hormone (GH) deficiency to elucidate the role of autoimmune disorders in the pathogenesis of GH deficiency. Antibodies to rat PCSA were assayed by ELISA. PCSA was detected in 15% of patients with GH deficiency, in contrast to that in healthy children and children with autoimmune thyroid diseases. The authors consider that in some cases GH deficiency may be caused by autoimmune hypophysitis. A family study revealed PCSA in 25% of mothers of patients with GH deficiency. In a population of healthy women PCSA was detected in 5.7% cases. Hence, a hereditary background of autoimmune abnormality cannot be completely ruled out.

Human prolactin and growth hormone induce specific proliferative responses in a culture of Nb2 rat lymphoma cells. These responses can be employed for characterization of the activity of serum immunoreactive prolactin and growth hormone in patients with endocrine disorders.

An immunosorbent with high binding capacity was developed using monoclonal antibodies specific to human growth hormone. Potential activity of the sorbent was studied in isolation of growth hormone from biological tissues and fluids. The immunosorbent enabled one to isolate the biologically and immunologically active growth hormone with high purity from the hypophyseal extract using only one step of purification. As shown by affinity chromatography and subsequent electrophoresis in polyacrylamide gel combined with radioimmunoblotting, together with predominant form of growth hormone, also intact and secreted from hypophysis, two-chain form of the hormone arising after proteolysis and large immunoreactive hormone fragments were detected in human circulation. These derivatives of the hormone may be also excreted with urine in unaltered form.

Stability of heterodimers of human glycoprotein hormones with gonadotropic and thyrotropic activities in sodium dodecylsulfate (SDS) under non-reducing conditions at low temperature permits to resolve the native molecules of these hormones in SDS-PAG and to distinguish from their dissociated subunits by electrophoretical mobility. The analysis of dimers and alpha-, beta-subunits in one polyacrylamide gel allows to detect certain human glycoprotein hormones and to study some of their physico-chemical properties. Using two polyclonal antisera against human LH and FSH by the Western blot immunoassay it was shown that heterodimers as well as alpha and beta subunits after SDS-PAGE retain antigenic activity of native hormones. The method gave possibility to characterize the specificity of the given sera to different glycoprotein hormones.

The time course of metabolic parameters and islet cell surface antibodies (ICSA) in low-dose streptozotocin (STZ)-induced diabetes in rats was studied, a total STZ dose being 160 mg/kg body weight. Two-phase diabetes development was observed. Initial mild hypoinsulinemia and hyperglycemia turned to more severe diabetes after day 24 which was preceded by the first ICSA peak at day 13. The second ICSA peak occurred at day 35. The data obtained suggest that in this model of diabetes the toxic STZ effect induces both the diabetic syndrome and humoral autoimmunity to beta-cells, and the latter leads to further impairment of diabetes.

Two stable hybridomas producing antibodies (Mab 1 and Mab 2) to bovine prolactin and belonging to the IgG1 subclass have been prepared. The cross-reactivity of Mab 1 and Mab 2 with some structurally similar pituitary protein (human, pig, whale, rat prolactins, bovine and human somatotropins) using indirect immunoenzymatic assay, was studied. It has been shown that Mab 2 reacts specifically only with bovine prolactin whereas Mab 1 interacts with human prolactin and prolactins of different animals. The specificity of Mab 1 to human prolactin was confirmed by immunoradiodetection assay on nitrocellulose filters. The data obtained give evidence of the existence of at least two different sterically nonoverlapping epitopes: one of them is specific exclusively for bovine prolactin and the other one is common, i.e. extraspecific.

The aim of present study was to obtain the hybridomas producing monoclonal antibodies against human growth hormone (Mabs hGH), to investigate the properties of the obtained Mabs and the possibility of their application in immunoanalytical systems. Two hybridomas secreting Mabs against hGH and belonging to the IgGI subclass have been obtained. The cross-reactivity of the Mabs with structurally similar to hGH hormones (hGHbio, hPL, hPRL, bGH, bPRL, pPRL) using indirect IFA has been studied. It has been shown that Mabs hGHI and Mabs hGH2 are directed to common specific antigenic determinant i.e. they have the same epitope specificity and don't react with other structurally related hormones, i.-e. this determinant is unique for hGH. The obtained Mabs hGH2 would find application for determination hGH by immunochemical methods in fractions while the hormone isolation from pituitaries and hGH obtained recombinant DNA methodology. The development of immunosorbents on the basis Mabs hGH2 seems to be perspective. Application of this immunosorbent may give possibility to optimize hormone isolation process.

Human somatotropin hormono (STH), produced by means of gene engineering in the complex program "Human growth hormone", managed by the Academy of Sciences of the USSR, Ministry of Medical and Biological Industry of the USSR and Ministry of Public Health of the USSR, was shown to be similar in its physico-chemical properties to the main isoform of highly purified STH, isolated from human hypophysis. As distinct from the hypophyseal STH (STHhyp) containing minor isoforms of the hormone, the preparation of biosynthetic STH (des-Phe1-STH; STHbio) proved to be homogeneous. Studies of biological properties showed that STHbio exhibited high, similar to STHhyp, immunological, growth-stimulating and insulin-like activities as well as it possessed the lipotropic effect in vivo. The lipotropic effect of STHbio in vivo was less prolonged as compared with that of STHhyp, while in vitro it was only slightly expressed in isolated rabbit fat tissue. The effect did not depend on the hormone dose, apparently due to either absence of the hormone modified forms in the STHbio preparation or other hypophyseal contaminating substances responsible for the lipotropic activity. STHbio, similarly to STHhyp, did not stimulate DNA synthesis in blood serum-free culture of human fibroblasts. Studies of STHbio biological properties suggest that multifunctionality of native STHhyp appear to depend on intrinsic specificity of its molecule.

A study was made of the effects of highly purified preparations of human and bovine pituitary somatotropin on DNA biosynthesis in fibroblast cultures from adults' skin. The intensity of DNA biosynthesis was evaluated from 3H-thymidine incorporation into the cells. It was established that both somatotropin preparations are capable of stimulating DNA synthesis by fibroblasts. However, simultaneous presence in the medium of the thermo- and acid-resistant fractions of rat blood serum is required for the stimulating effect of the hormone to manifest. It was found that the activity of blood serum factor inducing fibroblast sensitivity to somatotropin depends on the pituitary and rises after hypophysectomy.

Some new evidence on the biological activity of somatotropin fragment 77-107 is given. This fragment was prepared from whale somatotropin by tryptic hydrolysis. Beside the previously established ability of the hormone to increase the width of the tibial epiphyseal cartilage in hypophysectomized rats ("tibia" test) two other properties of the fragment indicative of its growth-promoting activity were established. The fragment enhances DNA biosynthesis in cultured human fibroblasts and increases the somatomedin content in blood serum of hypophysectomized rats. However, the fragment unlike the native hormone does not exert any metabolic action on adipose tissue "in vitro", i. e. does not stimulate the nonesterified fatty acid release into the medium. A comparison of the biological activity spectrum of native somatotropin and of its fragment 77-107 suggests that the biochemical information required for the realization of a prolonged growth-promoting effect and a relatively rapid action of the hormone on lipid and carbohydrate metabolism is contained in different parts of the polypeptide chain.

Synthetic tetradecapeptide corresponding to amino acid sequence 31–44 of human growth hormone molecule and possessing a lipotropic activity was tested for the ability to stimulate glucose uptake by isolated epididymal fat pads of fed rats. Tetradecapeptide 31–44 (1 μg/ml), growth hormone (1 μg/ml) and insulin (50 μU/ml) stimulated in about equal degree the uptake of [U- 14 C]glucose by adipose tissue. Tissue samples were preliminary incubated for 3–4 hours in the absence of hormones to eliminated the refractoriness to the insulin-like effects of growth hormone. Without preincubation the tissue was refractory to the action of growth hormone and tetradecapeptide 31–44, but was sensitive to insulin. The data obtained together with the findings of Lewis et al., which showed that 20K structural variant of human growth hormone having the deletion of residues 32–46 cannot stimulate glucose uptake and lipolysis in rats, make it possible to suggest that both activities are associated with fragment 31–44.