NISCAIR Online Periodicals Repository Collection: IJBB Vol.36(4) [August 1999]

IgG binding and expression of its receptor in rat intestine during postnatal development

Title: IgG binding and expression of its receptor in rat intestine during postnatal development

Authors: Gill, Ravinder Kaur; Mahmood, Safrun; Sodhi, C P; Nagpaul, J P; Mahmood, Akhtar

Abstract: The hinding of ¹²⁵1 labelled IgG to the microvillus membranes (MVM) has been studied during postnatal development of rat intestine. The levels of mRNA encoding IgG receptor were also analyzed by liquid hybridization under these conditions. The IgG hinding to MVM reached maximum levels by day 12 and showed a gradual decline upon weaning. The FcRn mRNA was markedly low in adult rats and was maximum during second week or postnatal development. Administration of cortisone or thyroxine to suckling rats, induced precocious decline of both IgG binding and the receptor expression. However, insulin administration did not affect the receptor expression. Scatchard an analysis of IgG binding to MVM in cortisone injected pups revealed that the observed inhibit ion in IgG binding was a consequence of a decrease, both in the affinity constant, (- Ka) as well as in the number of receptor sites (n) while thyroxine administration caused a reduction in the number of receptor sites from 2.29 in control to 1.14 nmoles/mg protein in thyroxine injected pups. These observations indicate that expression of IgG receptor during postnatal development is a hormone regulated process.

Page(s): 252-257

Targeting of piperine intercalated in mannose-coated liposomes in experimental leishmaniasis

Title: Targeting of piperine intercalated in mannose-coated liposomes in experimental leishmaniasis

Authors: Raay, Barnini; Medda, Swapna; Mukhopadhyay, Sibabrata; Basu, Mukul K

Abstract:

The leishmanicidal property of piperine intercalated in liposomes and in man nose-coated liposomes was tested in experimental visceral leishmaniasis in hamsters. Mannose-coated liposomal piperine eliminated intracellular amastigotes of Leishmania donovani in splenic macrophages much more efficiently than did the liposomal piperine or free piperine. At a dose equivalent to 6 mg/kg body wt every 4^th day for a total of 4 doses in 12 days, the mannose-coated liposomal piperine was found to reduce spleen parasite load to the extent of 90% in comparison to that achieved by liposomal piperine (77%) or free piperine (29%). Histological examination of spleen and liver function tests showed that the toxicity of piperine was reduced when mannosylated liposomal piperine was administered.

Page(s): 248-251

Nutritional properties of trans fatty acids

Title: Nutritional properties of trans fatty acids

Authors: Sambaiah, K; Lokesh, B R

Abstract: The role of trans fatty acids (TFA) present in partially hydrogenated fats widely consumed in food and their link with coronary heart disease has been examined in this review. Most of the studies carried out have been on the effects of TFA on blood-lipid profile. The perceived effects of TFA intake depend on the fat or oil with which they are compared and appears to be in between that of dietary saturated fats and monounsaturated fatty acids. When compared to saturated fat, TFA intake shows lower levels of total and LDL-cholesterol in blood. But when both TFA and saturated fatty acids are compared with cis fatty acids or native unhydrogenated oil, increase in total and LDL-cholesterol are noted. The effects of TFA on HD-cholesterol and Lp(a) are not clearly established. The undesirable effects of TFA can be overcome by inclusion of essential fatty acids at a minimum of 2 energy percent level in the diet. The link between trans fatty acid intake and coronary heart disease (CHD) are not unequivocally established.

Page(s): 211-220

Physicochemical characterization of hepatic glucocorticoid receptors from pre- and post-weaned mice

Title: Physicochemical characterization of hepatic glucocorticoid receptors from pre- and post-weaned mice

Authors: Borbhuiya, Monsur A; Sharma, Ramesh

Abstract: The physicochemical parameters viz., molecular weight, stokes radius and ionic state of hepatic glucocorticoid receptors from pre-(10-day) and post-(60-day) weaned mice were studied. Gel permeation studies of the crude receptors showed a molecular mass of ~290 kDa for the unactivated receptors from both the age groups while the thermally activated receptors showed a molecular mass of ~90 kDa. The stokes radii were ~5.8 and 3.6 for the unactivated and activated receptors, respectively from both the age groups studied. Elution of the bound glucocorticoid receptors from anion-exchanger did not reveal any charge difference in the two age groups; the unactivated receptors eluted at ~250 mM KCl whereas the activated receptors eluted at ~100 mM KCI. Salt extraction of thermally activated nuclear bound receptors and immunological studies on the unactivated receptors revealed no age-related variation in the two groups of mice. Our findings confirm that the physicochemical properties of hepatic glucocorticoid receptors remain unchanged at these developmental stages of mice.

Page(s): 240-247