Guinea Pig Adipose Tissue Research Articles

Time-dependent responses of brown fat in cold-exposed rats.

Time-dependent changes in metabolism, mass, composition, and total heat production of brown adipose tissue in cold-exposed rats

Comparison of the responsiveness of perirenal adipose tissue of the rat, hamster, guinea pig and rabbit to the antilipolytic action of insulin.

Previous studies in several laboratories have demonstrated marked species differences in the hormonal responsiveness of mammalian adipose tissue. The present investigation extends these comparative studies by comparing the antilipolytic potency of insulin upon the perirenal adipose tissue of rat, hamster, guinea pig and rabbit. Epididymal adipose tissue of the rat was also studied. Lipolysis was stimulated in vitro in slices of adipose tissue from these 4 species by incubation with 1 μg/ml epinephrine, adrenocorticotropin (ACTH) or β-melanocyte-stimulating hormone (β-MSH) in albumin-free, glucosefree Krebs-Ringer phosphate medium; the lipolytic response to these hormones, in the absence and presence of 0.00001-10 μg/ml insulin, was determined by measuring the free fatty acid (FFA) concentration in the tissue slices after a 2-hr incubation. Bovine insulin at a concentration of 0.0001-.001 μg/ml or greater inhibited the lipolytic response of rat adipose tissue to epinephrine or ACTH by 50-95 %. At a concent...

INACTIVATION OF THE ADIPOKINETIC PROPERTY OF ADRENOCORTICOTROPIN, BETA-MELANOCYTE-STIMULATING HORMONE, VASOPRESSIN AND PITUITARY FRACTION H BY TISSUES OF THE RAT AND RABBIT.

This report presents data on the rates of inactivation of 4 adipokinetic hypophysial peptides by adipose and extraadipose tissues of the rat and rabbit, and correlates these data with the in vitro and in vivo adipokinetic potencies of the peptides in these 2 species. The peptides under study (adrenocorticotropin, β-melanocyte-stimulating hormone, vasopressin and pituitary fraction H) were incubated for 1 hr with various tissue homogenates, and the adipokinetic activity remaining in the incubation mixture was then determined by introducing slices of rabbit, guinea pig, hamster or rat adipose tissue. The data showed: 1) Eight tissues of the rat (kidney, liver, adrenal, adipose tissue, lung, heart, testis and spleen) inactivate one or more of the peptides. 2) Ratios of the rates of inactivation of the 4 peptides vary markedly from one organ to another, and indicate the presence of at least 3 different inactivating enzymes in the rat. 3) While rat adipose tissue inactivates all 4 peptides under study, rabbit ...

Inactivation of adrenocorticotropin, α- and Β-melanocyte-stimulating hormones, vasopressin, and pituitary fraction H by adipose tissue

Rat adipose tissue homogenate contains a peptidase or group of peptidases which abolish the adipokinetic activity of ACTH, α-MSH, Β-MSH, vasopressin, and pituitary fraction H. The peptidase system is attached to an insoluble component in the homogenate. Homogenized rabbit adipose tissue inactivates only α-MSH, and homogenized guinea pig adipose tissue does not reduce the adipokinetic activity of any of the above hypophyseal peptides. Operation of the peptidase system in surviving slices of rat adipose tissue is suggested by these characteristics of this tissue: (a) rapid disappearance of adipokinetic activity from peptide-containing incubation medium; (b) absence of response to Β-MSH, vasopressin, or fraction H; (c) cessation of response to ACTH within 1 hr after exposure to the peptide is terminated. In contrast, slices of adipose tissue from the rabbit or guinea pig do not cause the disappearance of a detectable amount of activity from the medium; these slices are responsive to Β-MSH, vasopressin, and fraction H; their response to ACTH continues for at least 2 hr after exposure to the hormone is terminated. Differences between species in responsiveness of their adipose tissue to hypophyseal peptides appear to be related to differences in peptidase content of the fat cell.

EXPERIMENTAL NONTHROMBOCYTOPENIC VASCULAR PURPURA: A REVIEW OF THE JAPANESE LITERATURE, WITH PRELIMINARY CONFIRMATORY REPORT

Abstract Antisera were produced against guinea pig and mouse blood platelets, guinea pig and mouse spleen, mouse bone marrow, spleen, marrow plus spleen ("antireticulocytotoxic" serum), aqueous fraction of guinea pig adipose tissue rich in nonmuscular blood vessels, guinea pig choroid plexi rich in capillaries, whole guinea pig blood vessels, guinea pig smooth muscle, whole guinea pig blood vessel antiserum absorbed with guinea pig smooth muscle, and dog vascular endothelium. In all cases except the last named there were positive agglutinin and/or complement fixation titers, which were slightly enhanced anamnestically by whole adrenal cortical extract, but not by "Lipoadrenal" extract presumably high in "carbohydrate" factor. In no case was there a nonthrombocytopenic vascular purpura produced in vivo except by the anti-vascular endothelium serum. These preliminary observations are considered to confirm and extend observations made in previous reports in Japanese language periodicals, which are reviewed.