This study was designed to investigate the effects of cortisol on lipolysis in the common African toad Bufo regularis. Adult toads were collected and used for the study. The animals were fasted 24h and anaesthised by sodium thiopentone 50mg/kg intraperitoneally. Blood was collected from truncus arterious for estimation of blood glucose and blood free fatty acids levels. Cortisol caused significant increase in blood free fatty acids and glucose levels in the common African toad. Pretreatment with prazosin 0.2mg/kg produced significant reduction in blood free fatty acids but caused increase in blood glucose levels. Propranolol 0.5mg/kg pretreatment caused significant increase in blood free fatty acids and significant reduction in glucose levels. The combination of both blockers abolished the cortisol-induced hyperglycemia and caused significant reduction in blood free fatty acids. The results of this study confirmed that cortisol caused lipolysis from toad adipose tissue. Thus, cortisol administration caused increase in plasma free fatty levels and induced hyperglycemia. The alpha-adrenergic receptors are involved in the release of free fatty acids in the common African toad bufo regularis
Andrews R.C., and Walker B.R. (1999). Glucocorticoids and insulin resistance: old hormones, new targets. Clin. Sci. (Lond) 96:513 – 523
Arinze I., and Hanson R. (1973). Mitochondrial redox state and the regulation of gluconeogenesis in the isolated, perfused cat liver. FEBS Lett. 31: 280-282
Berneis K., Ninnis R., Girard J., Frey B. M., Keller U. (1997). Effects of insulin-like growth factor I combined with growth hormone on glucocorticoid-induced whole-body protein catabolism in man. J. Clin. Endocrinol. Metab. 82: 2528 – 2534.
Broughton R. E., and Deroos R. C. (1984). Temporal effects of infused corticosterone and aldosterone on plasma glucose levels in the American Bullfrog (Rara Castebiana). Gen. Comp. Endocrinol. 35:205 – 215
Campbell J.E., Peckett A. J., D ’Souza A. M, Hawke T. J., and Riddell M.C. (2011). Adipogenic and lipolytic effects of chronic glucocorticoid exposure, Am. J. Physiol. Cell. Physiol. 2011; 300(1):C198-209. [Pubmed: 20943959]
Chen X., Igbal N., and Boden G. (1999). The effects of free fatty acids on gluconeogenesis and glycogenolysis in normal subjects. J. Clin. Invest. 103: 365-372
Clore J. N., Glickman P. S., Helm S.T., and Nestler J. E., and Blackard W. G. (1991). Evidence for dual control mechanism regulating hepatic glucose output in nondiabetic men. Diabetes 40: 1033-1040.
Corredor C., Brandel K., and Bressler R. (1969). Effects of 4-pentenoic acid on carbohydrate metabolism in pigeon liver homogenate. J. Biol. Chem. 244: 1212-1219
Darmon P., Dadoun. F., Boullu-Ciocca S., Grino M., Alessi M. C., and Dutour A. (2006). Insulin resistance induced by hydrocortisone is increased in patients with abdominal obesity. Am J. Physiol. Endocrinol. Metab. 291: E995 – E1002.
Day J. L., Metcalfe J., Simpson C. N. (1982). Adrenergic mechanisms in control of plasma lipid concentrations Br. Med. J. 284: 1145-118
Dinneen S., Alzaid A., Miles J., and Rizza R. (1993). Metabolic effects of the nocturnal rise in cortisol on carbohydrate metabolism in normal humans. J. Clin. Invest. 92׃ 2283-2290.
Divertie G. D., Jensen M. D., and Miles J. M. (1991). Stimulation of lipolysis in humans by Physiological hypercortisolemia. Diabetes 40: 1228-1232
DJurhurus C. B., Gravholt C. H., Nielsen S., Mengel A., Christiansen J. S., Schmitz O. E., and Moller N. (2002). Effects of cortisol on lipolysis and regional interstitial glycerol levels in humans. AM. J. Physiol. Endocrinol. Meta :E172-177
Djurhuus C. B., Gravhol C. H., Nielsen S., Pedersen S. B., Moller N., and Schmitz O. (2004) Additive effects of cortisol and growth hormone on regional and systemic lipolysis in humans. Am. J. Physiol. Endocrinol. Metab. 286:E488-494. [Pubmed: 14600073]
Eckel R. H. (1989). Lipoprotein lipase. A multifunctional enzyme relevant to common metabolic diseases. N. Engl. J. Med. 320 : 1060-1068
Ferrannini E., Barrett E. J., Bevilacoua S., and Defronzo R. A. (1983). Effect of fatty acids on glucose production and utilization in man. J. Clin. Invest. 72׃ 1737- 1747
Fery F., Plat L., Melot C., and Balasse E. O. (1996). Role of fat derived substrates in the regulation of gluconeogenesis during fasting. Am. J. Physiol, 270: E822-E830
Fielding B. A., and Frayn K. N. (1998). Lipoprotein lipase and the disposition of dietary fatty acids. Br. J. Nutr. 80:495-502.
Geer E. B., Islam J., and Buettner C. (2014). Mechanism of Glucocorticoid-induced insulin resistance. Endocrinol. Metab. Clin. North. AM. 43 (1): 75 – 102
Gravoholt C. H., Dall R., Christiansen J. S., Moller N., Schmitz O. (2002). Preferential stimulation of abdominal subcutaneous lipolysis after prednisone exposure in humans. Obes. Res. 10׃774-781
Horber F. F., Haymond M. W. (1990). Human growth hormone prevents the protein catabolic side effects of prednisone in humans. J. Clin. Invest. 86:265 – 272
Imura H., Kato Y., Ikeda M., Morimoto M., and Yawata M. (1971). Effect of adrenergic blocking or stimulating agents on plasma growth hormone, immune reactive insulin, and blood free fatty acids levels in man. J. Clin. Invest. 50:1069-1079.
Isehunwa G. O., Olaniyan O. T., and Alada A.R.A. (2013). The role of alpha and beta adrenergic receptors in cortisol-induced hyperglycemia in the common African toad (Bufo regularis). Afri. J. Biotech. Vol. 12 (36), pp.5554-5558
Itaya K., and Ui M. (1965). Colorimetric determination of free fatty acids in biological fluids. J. Lipid Res, 6:16 – 20.
Jomain-Baum M., and Hanson R. (1975). Regulation of hepatic gluconeogenesis in the gunea pig by fatty acids and ammonia. J. Biol. Chem. 250: 8978-8985
Kovar J., Fejfarova V., pelikonova T., poledne R. (2004). Hyperglycemia down regulates total lipoprotein lipase activity in humans Physiol. Res. 53:61-68
Leach G. J., and Taylor M. H. (1982). The effects of cortisol treatment on carbohydrate and protein metabolism in Fundulus heteroclitus. Gen. Comp. Endocrinol. 48: 76 – 83
Lee M. J., and Fried S. K. (2012). Glucocorticoids antagonize tumor necrosis factor alpha- stimulated lipolysis and resistance to the antilipolytic effect of insulin in human adipocytes. Am. J. Physiol. Endocrinol. Metab.303: E1126-E1133
Lee M. J., Fried S. K., Mundt S. S et al. (2008).Depot-specific regulation of the conversion of cortisone to cortisol in human adipose tissue. Obesity (silver spring), 16 (6) 1126- 33
Lee M. J., Fried S. K., Mundt S. S., et al., (2008). Depot-specific regulation of the conversion of cortisone to cortisol in human adipose tissue. Obesity (Silver Spring) 16(6) 1126 – 33.
Macfarlane D. P., Forbes S., and Walker B. R. (2008). Glucocorticoids and fatty acid metabolism in humans: fueling fat redistribution in the metabolic syndrome. J. Endocrinol. 197: 189 – 204
Ottosson M., Lonnroth P., Bjorntorp P., and Eden S. (2000). Effects of cortisol and growth hormone on lipolysis in human adipose tissue. J. Clin. Endocrinol. Meta. 85:799-803.
Ottosson M., Vikman-Adolfsson K., Enerback S., Olivecrona G., Bjorntorp P. (1994). The effects of cortisol on the regulation of lipoprotein Lipase activity in human adipose tissue. J. Clin. Endocrinol. Metab. 79(3): 820 – 5
Pretty C., Chase J. G., Lim J., Shaw G., Compte A. L., Razak N., and Parente J. (2009). Corticosteroids and insulin resistance in the ICU proceedings of the 7th IFAC symposium on modelling and control in biomedical systems, Aalborg, Denmark
Puhakainen I., and Yki-Jarvinen H. (1993). Inhibition of lipolysis decreasing lipid oxidation and gluconeogenesis from lactate but not fasting hyperglycemia or total hepatic glucose production in NIDDM. Diabetes. 42: 1694-1699
Rizza R. A., Mandarino L. J., Gerich J. E. (1982). Cortisol-induced insulin resistance in man: impaired suppression of glucose production and stimulation of glucose utilization due to a postreceptor detect of insulin aaction. J. Clin. Endocrinol. Metab. 54: 131 -138
Samra J. S., Clark L., Humphreys S. M., MacDonald I. A., Banister P. A., and Frayn N K.N. (1998) Effects of Physiological hypercortisolemia on the regulation of lipolysis in subcutaneous adipose tissue. J. Clin. Endocrinol. Metab. 83:626-631. [Pubmed: 9467584]
Schote M. C and Page I. H. (1960). Effect of adrenergic blocking agents on the release of free fatty acids from rat adipose tissue. J. Lip. Res. Vo11(5) 466-468
Shaw J., England J. D. F., and Hua A. S. P. (1978). Beta-blockers and plasma tryglycerides. Br. Med. J. 486
Stimson R. H, Macfarlane D. P., Andrew R., Walker B. R., Anderson A. J. et al. (2017). Acute physiological effects of glucocorticoids on fuel metabolism in human are permissive but not direct. Diabetes Ches metab. 19׃883-891.
Trinder E. (1969). Determination of blood glucose using 4 amino phenazone as oxygen acceptor. J. Chem. Pathol. 22: 246-248
Trinder E. (1969). Determination of blood glucose using 4-amino phenazone as oxygen acceptor. J. chem. Pathol, 22, 246.
Xu C., He J., Jiang H. et al. (2009). Direct effect of glucocorticoids on lipolysis in adipocytes. Mol. Endocrinol. 23: 1161-1170
Zechner R. (1997). The tissue-specific expression of lipoprotein lipase: implications for energy and lipoprotein metabolism. Curr. Opin. Lipidol 8: 77 – 88.
This work is licensed under a Creative Commons Attribution 4.0 International License.
Copyright (c) 2021 African Journal of Biomedical Research