Cardiovascular responses induced by the activation of muscarinic receptors of the pedunculopontine tegmental nucleus in anesthetized rats.

BACKGROUND: The cardiovascular effects of nicotinic receptors of cholinergic system in the pedunculopontine tegmental nucleus (PPT) were shown. OBJECTIVE: In the following, the cardiovascular effects of the muscarinic receptor, another receptor in this system, were examined. METHODS: Rats were divided into eight groups: 1) control; 2 and 3) Ach (acetylcholine, an agonist) 90 and 150 nmol; 4 and 5) Atr (atropine; a muscarinic antagonist) 3 and 9 nmol; 6) Atr 3 + Ach 150; 7) Atr 9 + Ach 150; and 8) Atr 3 + hexamethonium (Hexa; 300 nmol) + Ach 150. After anesthesia, cannulation of the femoral artery was performed, and then the mean arterial pressure (MAP), systolic blood pressure (SBP), and heart rate (HR) were recorded using a power lab apparatus. RESULTS: Following drug microinjection, the maximum change (Δ) in MAP, SBP, and HR was calculated and analyzed. Both doses of Ach (90 and 150) significantly decreased ΔMAP and ΔSBP but could not change ΔHR. Neither of the doses of Atr significantly affected ΔMAP, ΔSBP, and ΔHR. Co-injection of Atr 3 + Ach 150 only increased ΔHR, but Atr 9 + Ach 150 decreased ΔMAP and ΔSBP than Ach 150 alone. The effect of the co-injection of Atr 9 + Hexa 300 + Ach 150 was also the same as the Atr 9 + Ach 150 group. CONCLUSION: The present results revealed that cholinergic muscarinic receptors in the PPT have an inhibitory effect on MAP and SBP with no important effect on HR.

Association of IL-10, IL-18, and IL-33 genetic polymorphisms with recurrent pregnancy loss risk in Iranian women.

Recurrent pregnancy loss (RPL) is a heterogeneous disease with three or more consecutive abortions before 20 weeks of pregnancy. Recently, inflammatory factors such as interleukins (IL) have been found to be a significant factor in the RPL. The objective of this study was to investigate the association between RPL and IL-10 (rs1800896), IL-18 (rs1946518) and IL-33 (rs1929992) genes polymorphisms in Iranian women. The study participants consisted of 300 women with RPL and the control group comprised of 300 healthy women with successful delivery. Genomic DNA was extracted from peripheral blood, and genotyping was performed by polymerase chain reaction (PCR) followed by restriction fragment length polymorphism (RFLP). There were no significant differences in the frequencies of genotype and allele in IL-10 gene polymorphism (rs1800896) between patients and control group (p > .005). In contrast, there were significant differences in the frequencies of CC genotype in IL-18 gene polymorphism (rs1946518) between patients and the control groups (p = .004; OR =0.990; 95% CI: 0.320-8.855). Also, there were significant differences in the frequencies of GA genotype in IL-33 gene polymorphism (rs1929992) between patients and the control groups (p = .001; OR =0.955; 95% CI: 0.239-9.807). Present study showed that the rs1800896 polymorphism (IL-10) might not play role in RPL in the Iranian population; whereas rs1946518 (IL-18) and rs1929992 (IL-33) polymorphisms may be associated with the risk of RPL in the Iranian women.

Evaluation of nicotinic receptor of pedunculopontine tegmental nucleus in central cardiovascular regulation in anesthetized rat.

OBJECTIVES: Cholinergic neurons are important neurons in the Pedunculopontine tegmental nucleus (PPT). In this study, nicotinic receptor of the PPT in central cardiovascular regulation in the anesthetized rat was evaluated. MATERIALS AND METHODS: Saline, acetylcholine (Ach; doses: 90 and 150 nmol), hexamethonium (Hexa; doses: 100 and 300 nmol) and higher doses of Hexa (300 nmol) + Ach (150 nmol) microinjected into the PPT. The femoral artery was cannulated and cardiovascular responses were continuously recorded by a power lab system. After injection of drugs, peak changes of mean arterial pressure (∆MAP), systolic blood pressure (∆SBP) and heart rate (∆HR) calculated and compared with saline group. RESULTS: The ∆SBP and ∆MAP significantly decreased by two doses of Ach (P<0.05 to P<0.001) but ∆HR did not change. Two doses 100 (P<0.05) and 300 nmol (P<0.01) of Hexa significantly increased ∆HR but did not alter the ∆MAP or ∆SBP. Co-injection of Hexa + Ach significantly strengthened the ∆HR induced by Hexa alone (P<0.01) but did not affect ∆MAP or ∆SBP. CONCLUSION: These results indicate that nicotinic receptor of the PPT has an inhibitory effect on ∆HR with no significant effect on ∆MAP or ∆SBP.

Cardiovascular effects of nitrergic system of the pedunculopontine tegmental nucleus in anesthetized rats.

OBJECTIVES: Nitric oxide (NO) is an important neurotransmitter in central nervous system involved in central cardiovascular regulation. The presence of NO in the pedunculopontine tegmental (PPT) nucleus has been shown, but its cardiovascular effect has not been determined. In the present study, the cardiovascular effect of NO in the PPT nucleus was evaluated. MATERIALS AND METHODS: After induction of anesthesia, a polyethylene catheter (PE-50) filled with heparinized saline inserted into the femoral artery, and the blood pressure (BP) and heart rate (HR) were continuously recorded. Animals were then placed in a stereotaxic apparatus and maximum changes of mean arterial pressure (∆MAP) and heart rate (∆HR) after microinjection of two doses of NG-nitro-L-arginine methyl ester (L-NAME, 30 and 90 nmol), L-arginine (L-Arg 10 and 50 nmol) and sodium nitroprusside (SNP, 9 and 27 nmol) into the PPT were provided and compared with control group (One-way ANOVA). RESULTS: Both doses of L-NAME significantly increased ∆MAP compared to control (P<0.05 and P<0.01, respectively). ∆HR only in higher dose (90 nmol) significantly increased compared to control (P<0.05). Two doses of L-Arg (10 and 50 nmol/150 nl) had no significant effect on ∆MAP or ∆HR. Higher dose of SNP (27 nmol) significantly decreased ∆MAP (P<0.05) and its both doses significantly decreased ∆HR compared to control (P<0.05 and P<0.001, respectively). Effect of higher dose on ∆HR was significantly higher than the lower dose (P<0.05). CONCLUSION: Our results show an inhibitory effect of the nitrergic system of the PPT on central cardiovascular system.