Catecholamine-stimulated lipolysis in adipocytes of spontaneously hypertensive rats.
We investigated the catecholamine-stimulated lipolytic response of perirenal adipocytes isolated from spontaneously hypertensive (SHR) and normotensive (C) rats of the Sprague-Dawley (SD) and Wistar-Kyoto (WKY) strain. Younger rats (10-17 weeks) were matched with respect to age and body weight. Age-matched SHR rats were smaller than their C counterparts, had equal-size adipocytes, and demonstrated lipolytic responses equal to C cells. Weight-matched SHR rats were older than normotensive controls, had larger adipocytes, and showed depressed norepinephrine (NE)-stimulated responses with a rightward shift in the dose-response curve. Rates of lipolysis of SHR and C cells were not different in the simultaneous presence of norepinephrine and theophylline. Nine- to ten-month-old rats were of comparable body weight and adipocyte size regardless of blood pressure status; however, SHR cells still showed a significantly blunted response to catecholamine stimulation. We conclude that (1) the NE-stimulated lipolytic response of adipocytes of SHR rats is significantly less than that elicited from C cells; (2) this function difference seems unrelated to a size difference between cells of younger, SHR and C rats, thus implicating the adrenergic system; and (3) whole body growth (as reflected by body weight) and perirenal adipocyte growth do not proceed in parallel in actively growing SHR rats.
D000273:Adipose Tissue / Q000033:anatomy & histology / Q000187:drug effects / Q000378:metabolism*; D000818:Animals; D001835:Body Weight; D006973:Hypertension / Q000378:metabolism* / Q000473:pathology; D008066:Lipolysis / Q000187:drug effects*; D009638:Norepinephrine / Q000494:pharmacology*; D051381:Rats; D011918:Rats, Inbred SHR; D011919:Rats, Inbred Strains; D011921:Rats, Inbred WKY; D011943:Receptors, Adrenergic, beta / Q000378:metabolism
D011943:Receptors, Adrenergic, beta; D009638:Norepinephrine