ABSTRACT
Background & objectives: Oxytocin (OT) injections to milch cattle for milk letdown have become a common practice amongst dairy farmers in India. Although there is no reported evidence, it is widely presumed that long term consumption of such milk leads to adverse health consequences. However, there is no information on the effect of exogenous OT injections on milk OT content and its stability during heating and gastrointestinal digestion. This study was carried out to determine the OT content in milk samples given by buffaloes with and without OT injections and to assess the stability of OT in the milk. Methods: Milk samples from milch buffaloes (Murrah buffalo) were collected from local farmers with (n=121) or without (n=120) exogenous OT injections during 3 to 5 months of lactation period. The OT content of milk samples was estimated by competitive enzyme immunoassay (EIA). The thermal and digestive stability of OT was assessed by in silico and in vitro digestion methods. Results: The OT content of the milk samples was similar regardless of OT injections used. Further, OT was found to be stable to heat treatment and gastric pepsin digestion while it was rapidly digested during the simulated intestinal digestion. reduced OT was digested by pepsin, implying that internal disulphide bridge of OT rendered the peptide resistant to peptic digestion. On the other hand, phenylmethylsulphonyl fluoride (PMSF), a serine protease inhibitor, abrogated the pancreatin induced digestion of OT. Interpretation & conclusions: These findings suggest that exogenous OT injections do not influence its content in milk. Further, OT present in milk is rapidly degraded during intestinal digestion, ruling out its intestinal absorption and associated adverse health consequences, if any.
ABSTRACT
Background & objectives: WNIN/Ob (obese and euglycaemic) and WNIN/GR-Ob (obesity with impaired glucose tolerance), were isolated and established from Wistar rat stock (WNIN). Both strains showed physical, physiological and biochemical indices related to obesity. We present here haematology, histology and pathophysiological changes between the phenotypes of these strains, lean (+/+), carrier (+/-) and obese (-/-). Methods: A total of 72 animals of equal gender consisting of three phenotypes were used for the study. Haematology, organ weights were measured and histopathology of the tissues studied using standard procedures. In 12 lean and obese rats (equal gender) of WNIN/GR-Ob group morphometry of pancreatic islets was done immunohistochemically (IHC). Results: Obese rats of both the strains showed normal haematology (except low platelet count), but exhibited changes in the organ weights and in histopathology in organs like liver, kidney, brain and testis/ovary. Hyperplasia of adipocytes was seen in obese rats as compared to lean and carrier. IHC of obese rat pancreas showed that both islet density and volume were significantly (P<0.05) increased compared to lean littermates. Interpretation & conclusions: The histological and pathophysiological changes seen in these mutants were in tune with obese phenotype exhibited by these animals.