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Biomedical subjects

A Gorbman

Publications and source records attributed to A Gorbman.

At least 55 records · Page 3Linked to original sources
PubMed1980

A stereotaxic atlas for diencephalic nuclei of the frog, Rana pipiens.

A stereotaxic apparatus was devised for frogs (Rana pipiens pipiens) by adaptation of a commercially available apparatus. An atlas of orienting illustrations emphasizing detailed structure and distribution of forebrain nuclei was prepared from celloidin sections and paraffin sections. Nomenclature of nuclei is discussed and an attempt made to reconcile various interpretations in the published literature.

Animals↗
PubMed1979

Rat gonadotropin release stimulated in vitro by GnRH-depleted rat brain extracts.

A study was made to compare the LH and FSH release patterns from isolated adult rat pituitaries in response to exposure to acidic extracts of rat hypothalamus or brain or to acidic extracts of GnRH-depleted hypothalamus, cerebral cortex, or cerebellum of adult (90-100 days old) or young (14 days old) rats of both sexes, using a continuous perifusion system. Hypothalami of adult rats contained 3-5 ng of radioimmunoreactive GnRH, while the corresponding cerebral cortex and cerebellum contained none, or extremely low levels of GnRH. Adult hypothalamic extract (HE) stimulated considerably greater LH and FSH release than was induced by cortical extract (CE) or cerebellar extract (CBE). Removal of assayable GnRH from HE by incubation with anti-GnRH serum reduced, but did not eliminate, release of both LH and FSH, suggesting that GnRH is the principal but not sole agent responsible for both LH and FSH secretions. Adult male HE released slightly more LH and FSH than did female HE due to its greater GnRH content. GnRH-depleted CE or CBE from both sexes induced LH and FSH releases qualitatively and quantitatively similar to those induced by CE, CBE or GnRH-depleted HE. Untreated extracts or GnRH-depleted extracts of all three brain regions from 14-day-old rats of both sexes induced similar LH and FSH releases as those of adult CE or CBE. Hypothalamus of young rats, which contained about 0.5 ng of immunoassayable GnRH did not release more LH and FSH than the corresponding cortex or cerebellum did. The data indicate that all brain regions so far studied, regardless of sex or age, contained presumably nonspecific substance(s), other than GnRH, capable of stimulating minor but significant LH and FSH releases. Their nature or role in physiological regulation of gonadotropin secretion is unknown, but must be considered, since current concepts, in which GnRH is the sole hypothalamic gonadotropin regulator, are not adequate.

Animals↗
PubMed1978

Some frontiers in comparative studies of the renin-angiotensin system.

A prospective survey on the comparative studies of the renin-angiotensin system (RAS) was made at the final session of the Japan-U.S. Cooperative Seminar, held on November 14--19, 1977, at Jichi Medical School, Tochigi-ken, Japan. Strategies and tactics of the research have been clarified. In morphological studies, the strategy is to clarify structure of the juxtaglomerular apparatus in representative species of vetebrate classes. In chemical studies, each component of the RAS must be established in each vertebrate class. Since we now know the existence of severel new angiotensins in vertebrates, their amino-acid sequences must be determined. They must be synthesized in sufficient purity. It is necessary to establish the international purity and assay criteria for synthetic angiotensins. In comparative studies on physiological aspects, the strategy is to establish the physiological roles of the RAS in vertebrate classes. Controls of blood pressure, of aldostrone secretion, of glomerular filtration rate and tubular transport, and of drinking and intestinal absorpiton are the candidates. Physiological roles of extrarenal renin as well as renal one are interesting. A renin-like substance in the corpuscles of Stannius in the teleosts has been identified preliminarily as hypocalcin. Many frontiers exist in these fields, and one can expect fruitful contributions to research of the cardiovascular disease in humans through comparative studies of the RAS.

Amino Acid Sequence↗
PubMed1977

Effects of cholecystokinin, gastrin, and related peptides on coho salmon gallbladder contraction in vitro.

UNLABELLED: Isometric contractions of coho salmon (Oncorhynchus kisutch) gallbladder longitudinal muscle strips were recorded in response to porcine cholecystokinin (CCK), octapeptide of CCK (OP-CCK), desulfated octapeptide of CCK (ds-OP-CCK), porcine heptadecapeptide gastrins I and II, and pentagastrin. Peak tonic contraction amplitude and peak rhythmic contraction frequency were used to construct concentration-response curves for each peptide. Observed maximal responses to each peptide were not significantly different; therefore, all peptides tested were equal in efficacy. CCK, OP-CCK, and gastrin II were equipotent, and ds-OP-CCK and gastrin I were equipotent. CONCLUSIONS: 1) porcine CCK can stimulate contraction of the coho salmon gallbladder; 2) tonic and rhythmic contractile responses are elicited in coho salmon gallbladder by agonists; 3) coho salmon gallbladder muscle cannot distinguish between agonists that differ in the location of a sulfated tyrosyl residue at position 6 versus position 7 from the C-terminus; and 4) the results of this study are consistent with the hypothesis that coho salmon gallbladder muscle contains a relatively primitive CCK receptor.

Acetylcholine↗