en Cardiovascular Physiology/Pharmacology Cardiovascular Physiology/Pharmacology Experimental research article Experimental research article <p dir="ltr" style="text-align: justify;"><span style="font-size: 12px;"><span style="font-size: 12px;"><b>Introduction: </b><font face="Arial,Arial"><font face="Arial,Arial">Resistin, a complex multimeric structure which is secreted by adipose tissue and circulates in the blood, acts on the hypothalamus to increase sympathetic nerve activity, inhibit appetite and is associated with obesity, insulin resistance and cardiovascular disorders. In this study, we survey the cardiovascular effects of direct injection of resistin into specific cell group of the paraventricular nucleus (PVN) that is known as one of the centers which control the baseline of arterial pressure and heart rate. <span style="font-size: 12px;"><b>Methods: </b><font face="Arial,Arial"><font face="Arial,Arial">Adult male rats were anesthetized with urethane (1.4g/kg intraperitoneally). Arterial pressure (AP) and heart rate (HR) were monitored before and after treatment. Resistin (1, 3 and 5&mu;g/rat), norepinephrine (2.5 nM), muscimol (250ng/rat) and saline as control (vehicle solution, 1&mu;l) were injected into the PVN parvocellular neurons. <span style="font-size: 12px;"><b>Results: </b><font face="Arial,Arial"><font face="Arial,Arial">The results showed that resistin (3 and 5&mu;g/rat) caused a significant increase in AP, HR and high QRS compared to control group and prior to its injection. Injection of norepinephrine into the PVN evoked a significant increase in AP, HR and QRS amplitude, whereas injection of muscimol significantly decreased these parameters. In the control group, saline injection into the PVN had no significant effect on these parameters. <span style="font-size: 12px;"><b>Conclusion: </b><font face="Arial,Arial"><font face="Arial,Arial">It can be concluded that the PVN can be one of the important central areas for actions of resistin which had obvious effects on HR and AP. These results provide a base for future studies to explore the role of resistin in cardiovascular responses in conditions like metabolic syndrome and hypertension.</font></font></span></font></font></span></font></font></span></font></font></span></span></p> Resistin, Paraventricular Nucleus, Heart Rate, Arterial Pressure 216 224 http://ppj.phypha.ir/browse.php?a_code=A-10-991-1&slc_lang=en&sid=1 Abolfazl Akbari 3200319475328460018184 3200319475328460018184 No Department of Physiology, School of Veterinary Medicine, Shiraz University, Shiraz, Iran Gholamali Jelodar jelodar@shirazu.ac.ir 3200319475328460018185 3200319475328460018185 Yes Department of Physiology, School of Veterinary Medicine, Shiraz University, Shiraz, Iran