Identification and location of the cocaine and amphetamine regulated transcript (CART) in the abomasum of cattle

The relationship of body condition and chewing time with body weight, the level of plasma cocaine and amphetamine regulated transcript, leptin and energy metabolites in cows until reaching the lactation peak

This study examined the relationship of body condition and chewing time (CT) with body weight (BW), the level of cocaine-and amphetamine-regulated transcript (CART), leptin and energy metabolites in cows until reaching the lactation peak. The results showed the greatest loss of BW between days 11 and 45 of lactation and a decrease in the body condition score (BCS) until day 75. Chewing time showed an increase from day 45 with the highest values after lactation peak. The CART and leptin concentrations demonstrate a reduction of both indices (P < 0.05) between days 11 and 75. The function of leptin as a factor positively correlating with BW and BCS was found. In the heaviest individuals and those with higher BCS, the blood leptin levels were higher. The results of beta-hydroxybutyrate (BHBA) indicate that cows with the lowest BCS had the most intensive energy transformation. This led to a higher BHBA concentration compared to the cows with high BCS (P < 0.05). The obtained results show that CART was most strongly negatively associated with CT (P < 0.05). For leptin, the tendency was the opposite and the correlation with CT was not significant. The results suggest that CT may be stronger regulated by CART, which has anorectic properties, than by appetite inhibiting leptin. Significant decrease of body condition during lactation is a great problem for dairy farmers. The explanation of the issue of the participation of CART and leptin in the regulation of body’s energy homeostasis may therefore be of importance for milk production.

T2 Toxin-Induced Changes in Cocaine- and Amphetamine-Regulated Transcript (CART)-Like Immunoreactivity in the Enteric Nervous System Within Selected Fragments of the Porcine Digestive Tract

T-2 toxin is a mycotoxin produced by some Fusarium species, which may affect the synthesis of DNA and RNA and causes various pathological processes. Till now, the influence of T-2 toxin on the enteric nervous system (ENS) located in the wall of gastrointestinal tract has not been studied. On the other hand, cocaine- and amphetamine-regulated transcript (CART) is one of enteric neuronal factors, whose exact functions in the intestines still remain not fully explained. The present study describes the influence of low doses of T-2 toxin on CART-positive neuronal structures in porcine stomach, duodenum, and descending colon. Distribution of CART was studied using the double immunofluorescence technique in the plexuses of the ENS, as well as in nerve fibers within the circular muscle and mucosal layers of porcine gastrointestinal tract. Generally, after T-2 toxin administration the greater number of CART-LI structures were studied, but intensity of changes depended on part of the ENS and digestive tract fragment studied. The obtained results show that even low doses of T-2 toxin may change the expression of CART in the ENS.

Correlation between the cocaine- and amphetamine-regulated transcript in the pyloric section of the abomasum and fat deposition in bulls’ carcasses

The study was aimed at investigating the relationship between the number of cocaine- and amphetamine-regulated transcript (CART) structures present in the pyloric section of the abomasum and fat accumulation in carcasses of bulls – crosses of Polish Lowland Black-and-White cows mated with Limousin bulls. The bulls were slaughtered at the mean age of 629 days and body weight of 597 kg. The distribution of cocaine- and amphetamine-regulated transcript-immunoreactive in the pyloric section of abomasum was assessed on the basis of CART positive immunohistochemical reactions. Significant interdependence was found between the number of CART structures and carcass adiposity and the fat content of the longissimus lumborum muscle. The identified tendency for fat tissue increase in the carcasses was accompanied by a lower concentration of the structures. In the endocrine system cell the greatest number of immunopositive cells were found; ranging from 28.9 in animals more obese to 37.8 with the smallest amount of fat accumulated. The lowest numbers of immunopositive cells, ranging from 2.4 to 3.9 were noted in the submucous plexus layer. Slightly more structures were observed in nerve fibres and the myenteric plexus, at 2.9 and 4.7, respectively. The number of CART in the endocrine system was correlated with subcutaneous fat (-0.451) and marbling (-0.514). The amount of CART in these anatomical layers was significantly correlated with the thickness of subcutaneous fat (-0.541 and -0.636) and the weight of perinephric fat (-0.487 and -0.672). The results confirm that CART is an important neurotransmitter that participates in the regulation of fat deposition in the body. It must be stressed that the correlations with the analysed fat deposition indices concerned the adiposity indicators influencing the commercial value of carcasses and the meat traits important to the consumer.

Immunodetection of cocaine- and amphetamine-regulated transcript in bovine pancreas

This study was aimed at identifying and determining the configuration of structures which contain the cocaine- and amphetamine-regulated transcript peptide (CART) in the bovine pancreas. The study material was collected from 20 animals. The distribution of CART in the bovine pancreas was investigated, by an immunohistochemical evaluation. CART peptide in the normal pancreas has been identified in intrapancreatic ganglia, nerve fibres and in endocrine cells of Langerhans islets and exocrine pancreas. CART immunoreactive nerve fibres innervate the exocrine and endocrine regions and the intrapancreatic ganglia, where they form a moderate number of networks, encircling the cell bodies. The few CART-immunoreactive endocrine cells, that appear in the bovine pancreas, are not limited to the islet cells, where they form a subpopulation of CART-containing cells, but are also individually distributed in the exocrine region. Furthermore, CART has been visualized in nerve fibres, innervating pancreatic outlet ducts and blood vessels. CART plays a physiological role in the integrated mechanisms that regulate both endocrine and exocrine pancreatic secretion. These results are consistent with the hypothesis that CART expression in nerve fibres and intrapancreatic ganglia is a common feature of the mammalian pancreas, whereas its expression in endocrine cells appears to be restricted to single cells of the bovine pancreas.

Quantitative evaluation of CART-containing cells in urinary bladder of rats with renovascular hypertension

Recent biological advances make it possible to discover new peptides associated with hypertension. The cocaine- and amphetamine-regulated transcript (CART) is a known factor in appetite and feeding behaviour. Various lines of evidence suggest that this peptide participates not only in control of feeding behaviour but also in the regulation of the cardiovascular and sympathetic systems and blood pressure. The role of CART in blood pressure regulation led us to undertake a study aimed at analysing quantitative changes in CART-containing cells in urinary bladders (UB) of rats with renovascular hypertension. We used the Goldblatt model of arterial hypertension (two-kidney, one clip) to evaluate quantitative changes. This model provides researchers with a commonly used tool to analyse the renin-angiotensin system of blood pressure control and, eventually, to develop drugs for the treatment of chronic hypertension. The study was performed on sections of urinary bladders of rats after 3-, 14-, 28-, 42 and 91 days from hypertension induction. Immunohistochemical identification of CART cells was performed on paraffin for the UBs of all the study animals. CART was detected in the endocrine cells, especially numerous in the submucosa and muscularis layers, with a few found in the transitional epithelium and only occasionally in serosa. Hypertension significantly increased the number of CART-positive cells in the rat UBs. After 3 and 42 days following the procedure, statistically significantly higher numbers of CART-positive cells were identified in comparison with the control animals. The differences between the hypertensive rats and the control animals concerned not only the number density of CART-immunoreactive cells but also their localization. After a 6-week period, each of the rats subjected to the renal artery clipping procedure developed stable hypertension. CART appeared in numerous transitional epithelium cells.

As this study provides novel findings, the question appears about the type of connection between hypertension and the functioning and activity of CART in the urinary tract (UT). The study gives rise to the assumption that high blood pressure can be a factor that intensifies CART secretion. In conclusion, the endocrine system of the urinary tract is modified by renovascular hypertension. This may affect the production of hormones and biologically active substances and contribute to the development of possible hypertension complications. In order to fully comprehend the role of the CART peptide in blood pressure regulation, further analyses are necessary.