Factors Influencing the Lipolytic Response of Swine (&lt;i&gt;Sus domesticus&lt;/i&gt;) Adipose Tissue: Ontogeny

Mersmann, Harry J.; Phinney, G.; Brown, L. Jackson

doi:10.1159/000240854

Cited by 9 publications

(2 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

Section: Other Lipase Activitiesmentioning

confidence: 97%

Hormonal and dietary regulation of lipolysis in bovine adipose tissue

DiMarco

View full text Add to dashboard Cite

Effect of exogenous prostaglandin E2 on rates of lipolysis in sections of subcutaneous adipose tissue biopsied from fed and 9-day fasted Hclstsin steers was determined. The interaction of prostaglandin E2 with exogenous effectors of lipolysis and of the adenylate cyclase-cAI-IP system (epinephrine, dibutyryl cAI-IP, and theophylline) also was measured. Rates of lipolysis were expressed as the amount of glycerol released from adipose tissue incubated for two hours. Epinephrine increased the rate of basal (nonstimulated) lipolysis by 1.9-fold. Prostaglandin E2 had no effect on either basal or epinephrine-stimulated rates of lipolysis. Dibutyryl cAMP increased basal rates of lipolysis by 1.4-fold; this increase, however, was less than the stimulation observed with either epinephrine or theophylline which increased basal rates of lipolysis by more than 2-fold, Theophylline had an additive effect on epinephrine-stimulated rates of lipolysis. Dibutytyl cAMP increased theophylline-stimulated rates of lipolysis but not those of epinephrinestimulated lipolysis. Prostaglandin E2 had no effect on epinephrine-, dibutyryl cAfIP-, or theophylline-stimulated rates of lipolysis. Fasting decreased the basal rate of lipolysis by 40 percent. Furthermore, rates of lipolysis in tissue incubated with PGE2 , epinephrine, or PGE2 plus epinephrine decreased from 30 to 50 percent because of the 9-day fast. As also shown in tissue from, fed steers, PGEo did not alter basal or epinephrine-stimulated rate^ of lipolysis in tissue from fasted steers. These comparisons of rates of lipolysis in adipose tissue from fed and iv fasted steers indicate that prostaglandin E2 does not control the adenylate cyclase-cAI-IP system that regulates lipolysis in bovine adipose tissue. LITERATURE REVIEW This literature review will describe the morphology and biochemistry of the fat cell and regulation of lipid metabolism in the fat cell by diet and hormones and will relate these parameters to fat deposition in the meat animal. Characterization of Adipose Tissue Components of adipose tissue Kauffman's definition of fat states that "fat is the collection of adipose cells suspended in a layer of connective tissue matrix that are distended with cytoplasmic lipids, water^ and other constituents" (1976). The other constituents are collagen fibers, fibrocytes, histocytes, mast cells, and unmyelinated nerve fibers (VJasserman, 1965), In .meat animals, white fat constitutes the major type, although brown fat does exist in young and especially hibernating animals. Brown fat is characterized by its higher concentration of mitochondria and its high rate of respiration (Fain and Reed, 1970). As the adipocyte matures, it is believed to acquire a predetermined size and volume dependent upon its anatomical location, age, species, and state of nutrition (Kauffman, 1976). In the bovine species, the largest intramuscular adipocytes are 170 um in diameter while those from sub cutaneous or perirenal depots in the same animal are larger ("«200 to 220 ym in diameter) (Allen, 1976). ...

show abstract

Section: Other Lipase Activitiesmentioning

confidence: 97%

Hormonal and dietary regulation of lipolysis in bovine adipose tissue

DiMarco

View full text Add to dashboard Cite

show abstract

“…Swine adipose tissue is not responsive to glucagon at any age and only marginally to ACTH; however, the response to ACTH is greatly increased by the addition of theophylline (Mersmann , 1976a;b)> Etherton et al, (1977) indicated that glucagon had no effect on glycerol or free fatty acid release in both sheep and cattle adipose tissue. On the other hand.…”

Section: Other Lipase Activitiesmentioning

confidence: 98%