Protective efficacy of trypsin inhibitor on the the gut following rotavirus infection in malnourished infant mice

Mild-to-moderate malnutrition alters glutathione, gamma-glutamyl-transpeptidase and glycine uptake in small intestinal brush-border vesicles of rhesus monkeys

BACKGROUND

In India about 85% of pre-school children show evidence of mild-to-moderate malnutrition. Consequences of severe malnutrition and protein deficiency are well reported by workers but little information is available on milder forms.

METHODS

Mild-to-moderate protein energy malnourished (PEM) state was induced in 12 monkeys by providing 2.42 g protein and 55 kcal kg(-1) day(-1) while 12 controls were fed 4.84 g protein and 110 kcal kg(-1). After a 30-40% reduction in body weight as compared with their controls, the animals were killed and brush border membrane vesicles (BBMV) were prepared from three parts of small intestine. Purified vesicles were assayed for gamma-glutamyl-transpeptidase (GGTP), glutathione (GSH) and U-(14)C-glycine uptake.

RESULTS

GGTP activity increased significantly while glutathione and uptake of glycine decreased significantly in all the three parts of small intestine. On nutritional rehabilitation of 9 weeks, the activity of GGTP, GSH and in vitro uptake of glycine amino acid recovered completely.

CONCLUSION

The results of the present study indicates that even mild-to-moderate malnutrition should not be ignored during the development state.

Influence of soybean trypsin inhibitor on small bowel enzyme activities during rotavirus infection in malnourished infant mice

Rotavirus (RV) is considered to be one of the major causes of acute episodic diarrhoea throughout the world. This study was undertaken to investigate the effect of soybean trypsin inhibitor (TI) on brush-border enzymes during rotavirus infection in protein energy malnourished (PEM) infant mice. Animals were divided into 4 groups, namely controls, PEM, PEM+RV and PEM+RV+TI (n = 36 each). Group 1 and 2 animals were orally inoculated with 50 microl of normal saline each. Group 3 animals were orally inoculated with 50 microl of 100 ID50 dose of RV stock each. Group 4 animals were similarly inoculated with 0.6 mg TI/g body weight along with 50 microl of RV stock each. Animals were examined daily for diarrhoea and their body weight was recorded on alternate days postinoculation (dpi). Animals were killed by cervical dislocation after being given light chloroform anesthesia on 0, 1, 3, 5, 7 and 10 dpi. Small intestines were excised and homogenized in normal saline. Proteins, gammaglutamyl transpeptidase, alkaline phosphatase and disaccharidases were estimated in jejunum and ileum. Body weight was significantly reduced in PEM animals and with RV infection. Histologically, focal areas of vacuolar degeneration of lining epithelium were seen in RV-infected animals. Disaccharidases and other enzyme activities were decreased significantly in the PEM group compared to healthy controls and further depressed with RV infection in malnourished animals as compared to non-infected PEM. The enzyme activities were restored in animals receiving TI along with RV compared to the group receiving RV without TI. With the administration of soybean TI, the activities of disaccharidases, alkaline phosphatase, gammaglutamyl transpeptidase and intestinal architecture were restored showing a protective effect in PEM during RV infection.

Imaging neurochemical endophenotypes: promises and pitfalls

A large number of polymorphisms in genes coding for neurotransmitter receptors and transporters have been associated with neuropsychiatric conditions, although few of these associations have been consistently replicated. These proteins are critical targets of psychoactive drugs and the clarification of the functional significance of these polymorphisms might offer important leads for drug development and therapeutic applications. Brain imaging techniques such as single photon emission computed tomography (SPECT) and positron emission tomography (PET) provide the means to monitor the expression and function of many of these proteins in the living human brain. This paper reviews brain imaging studies designed to evaluate the significance of polymorphisms in genes coding for important drug targets (e.g., the serotonin transporter [SERT], the dopamine transporter [DAT] and the dopamine D(2) receptor) in terms of expression or function. These studies illustrate the unique opportunities, as well as the pitfalls, generated by combining genetic analysis with brain imaging studies.