ABSTRACT
Rat plasma kallikrein (RPK) is a serine protease that circulates as an inactive precursor, prokallikrein, and once activated is efficiently cleared by the liver by a carbohydrate-dependent, Ca2+ - independent mecanism. Seven hepatic lectin systems have been described for mammals but not all of these animal lectins are expressed in the avian liver. Using a liver perfusion system we compared the plasmakallikrein clearance of rats (N=10) and pigeons (N+4). Our results show that the lectin responsible for the hepatic clearance of plasma kallikrein is also present in pigeon liver and that this organ clears the enzyme with an efficiency (11.4 ñ 1.3 pmol/g,20 min) similar to that of the rat liver (10.0 ñ 0.7 pmolg, 20 min)_
Subject(s)
Rats , Animals , Liver/metabolism , Kallikreins/blood , Columbidae , Kallikreins/metabolism , Metabolic Clearance Rate , Receptors, Mitogen/pharmacologyABSTRACT
In view nof the known interactions between pineal and adrenal glands and the importance of glucocorticoids on the acute phase of the inflammatory process, we investigated the effect of the pineal gland on the paw edema response induced by carrageenin in female Wistar rats, weighing 170-220 g, measured by the pletysmographic method. Adrenalectomy increased the rate of the inflammatory response (149.02 ñ 2.93%, N=7 vs 113.48 ñ 2.99%, N=7) whereas pinealectomy and sham-pinealectomy under white light had an inhibitory effect (81.73 ñ 2.16%, N=15 and 80.21 ñ 1.85%, N=14 vs 113.48 ñ 2.99%, N=7). Sham-pinealectomy under red light did not modify the rate of the inflammatory response. These results indicate that the pineal gland can be affected by light during sham-pinealectomy. In view of the unaltered adrenal gland weight and corticosterone levels among the different groups, we propose an antagonism between melatonin (pineal hormone) and glucocorticoids at the peripheral level. The predominant effect of glucocorticoids over melatonin may explain the inhibition of the inflammatory response caused by pinealectomy
Subject(s)
Rats , Animals , Female , Acute-Phase Reaction/etiology , Adrenalectomy , Carrageenan/pharmacology , Light , Pineal Gland/surgery , Corticosterone/blood , Melatonin/biosynthesis , Melatonin/pharmacology , Rats, Inbred StrainsABSTRACT
The effect of sex steroids on the plasma levels of alfa2-macroglobulin (alfa-2M) was investigated to explain the sexual dimorphism observed in response to the injuries caused by ip administration of 5 microng endotoxin. Mean serum alfa2-M concentrations were lower in female (46.82 ñ8.10 arbitrary units) than in male injured rats (82.94 ñ 9.22 arbitrary units). a reduction of plasma alfa2-M levels was observed after orchidectomy, and the administration of 1 mg testosterone to the same animals increased the response. The same response pattern wa observed in ovariectomized rats under the same treatment. The response of androgenized rats (78.93 ñ 12.81 arbitrary units) to injury was similar to the male response. These results suggest the importance of testosterone as the major determinant of this sex-dependent response
Subject(s)
Rats , Animals , Male , Female , Acute-Phase Reaction/etiology , alpha-Macroglobulins/metabolism , Sex Characteristics , Gonadal Steroid Hormones/pharmacology , Endotoxins/pharmacology , Orchiectomy , Ovariectomy , Rats, WistarABSTRACT
Acute phase response of plasma alfa-1-major acute phase (alfa1-MAP) was studied in normal and adrenalectomized rats. Alfa1-MAP basal levels were higher in female than in male rats. This proteins, measured by radial immunodiffusion, increased significantly both in male and female rats 24 and 48 h after a turpentine stimulus, proving to be a positive acute phase protein for both sexes. In adrenalectomized male rats the increase of plasma alfa-1MAP concentration was not different from that observed in sham-operated rats, suggesting that the acute phase response of this protein is not corticoid dependent
Subject(s)
Rats , Animals , Male , Female , Adrenalectomy , alpha 1-Antitrypsin/analysis , Corticosterone/blood , Turpentine/pharmacology , Rats, WistarABSTRACT
Rats treated with monosodium glutamate (MSG) during the neonatal period show hypothalamic lesions and multiple neuroendocrine alterations manifested as a remarkable increase in levels of circulating corticosterone and obesity. Paw edema induced by local injection of carrageenin was significantly reduced in MSG-treated rats compared to normal rats. In contrast, both adrenalectomized rats and adrenalectomized, MSG-treated rats showed an increased response to carrageenin relative to controls. These results suggest that glucocorticoids are important modulators of inflammation in this phase of the process