Dissertation > Excellent graduate degree dissertation topics show

Hypoxic Adaptation of the Hearts of Plateau Zokor (Myospalax Rufecens Baileyi) and Plateau Pika (Ochotona Curzoniae)

Author: QiXinZhang
Tutor: WeiDengBang
School: Qinghai University
Course: Animal Nutrition and Feed Science
Keywords: Plateau zokor (Myospalax rufecens baileyi) Plateau pika (Ochotona curzniae) Hypoxia Cardiac muscle heart
CLC: Q41
Type: Master's thesis
Year: 2009
Downloads: 41
Quote: 0
Read: Download Dissertation

Abstract

Plateau zokor (Myospalax rufecens baileyi) and plateau pika (Ochotona curzniae) are native to the Qinghai-Tibet plateau. To study their adaptive mechanisms, the ratios of heart weight to body weight (HW/BW) and right to left ventricular plus septum weights [RV/(LV+S)] were determined; the microvessel density (MVD) of cardiac muscle were measured by immunohistochemical staining; the numerical density on area (NA), volume density (VV), specific surface (δ), and surface density (SV) of mitochondria were obtained by microscopy and stereology; the content of myoglobin (Mb), lactic acid (LD) and the activity of lactate dehydrogenase (LDH) in cardiac muscle were analyzed by spectrophotometer; the expression levels of gene Hypoxia-inducible factor-1α( HIF-1α) , Mb, Vascular endothelial growth factor 165(VEGF165), LDH-A and LDH-B were detected by real-time PCR.The results showed that the HW/BW of plateau zokor [(4.55±0.26)%] and plateau pika [(4.41±0.38)%] were significantly greater than that of Sprague-Dawley (SD) rat [(3.44±0.41)%] (P<0.05), but the RV/(LV+S) [(22.04±1.98)%, (25.53±3.41)%] were smaller than that of SD rat [(44.23±3.87)%] (P<0.05). The NA of cardiac muscle was 0.768±0.123 in SD rat, 0.868±0.159 in plateau pika and 1.012±0.133 in plateau zokor. The VV of mitochondria in plateau zokor (0.272±0.045) was significantly lower than those in plateau pika (0.343±0.039) and SD rat (0.321±0.048) (P<0.05), while theδof mitochondria in plateau zokor (9.409±1.238) was higher than those of plateau pika and SD rat (6.772±0.892 and 7.287±1.373) (P<0.05). The SV of mitochondria in plateau pika (2.322±0.347) was not obviously different from that of plateau zokor (2.468±0.380) and SD rat (2.227±0.377), but that of plateau zokor was significantly higher than that of SD rat (P<0.05). The expression level of gene HIF-1αin cardiac muscle of plateau pika (0.45±0.06) had no significant different from plateau zokor (0.51±0.08) and SD rat (0.38±0.05), but that of plateau zokor was obviously higher than that of SD rat (P<0.05). The expression level of Mb mRNA in cardiac muscle of plateau zokor (0.98±0.03) was notably lower than that of pika (1.15±0.39) which was also notably lower than that of SD rat (1.25±0.72) (P<0.05). The contents of Mb in cardiac muscle of plateau zokor [(763.33±88.73) nmol/g] and plateau pika [(765.96±28.47) nmol/g] were significantly higher than that of SD rat [(492.38±72.14) nmol/g] (P<0.05). The expression level of gene VEGF165 in cardiac muscle of plateau zokor (1.52±0.07) was significantly lower than that of SD rat (1.76±0.17), which of plateau pika (1.64±0.08) was slightly higher than plateau zokor and lower than SD rat but the MVD of the cardiac muscle of plateau zokor (2990.643±389.888) was notably higher than plateau pika (2002.888±367.466) which was also notably higher than SD rat (1688.631±250.253). Plateau zokor (1.423±0.031 and 1.167±0.079) and plateau pika (1.305±0.052 and 1.422±0.025) had great higher expression levels of gene LDH-A and LDH-B in cardiac muscle than those in SD rat (1.128±0.164 and 1.023±0.098) (P<0.05), while the contents of LDH-B mRNA in cardiac muscle of plateau pika was significantly higher than that of plateau zokor. The content of LD in plateau zokor [(0.57±0.06) mmol/L] was obviously higher than that of plateau pika [(0.45±0.06) mmol/L] and SD rat [(0.48±0.02) mmol/L] (P<0.05), and the activity of LDH in plateau zokor [(16.90±2.00) U/mL] and plateau pika [(20.55±2.46) U/mL] were significantly lower than that of SD rat [(38.26±6.78) U/mL] (P<0.05). The percentage of LDH-H in cardiac muscle decreased in order in plateau zokor, plateau pika and SD rat.In conclusion, there were some features were same or similar in the heart of plateau zokor and plateau pika, that made their heart could pump more blood, increase the diffusion efficiency of oxygen from blood to mitochondria, use the oxygen more effectively and have a higher stress ability. However, they were very differently from each other in some ways. It should because of their different habitats and habits.

Hypoxic Adaptation of the Hearts of Plateau Zokor (Myospalax Rufecens Baileyi) and Plateau Pika (Ochotona Curzoniae)

Abstract

Related Dissertations