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41.
Yuta NAGAI Takeharu KANEDA Yasuyuki MIYAMOTO Takaomi NURUKI Hidenori KANDA Norimoto URAKAWA Kazumasa SHIMIZU 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2016,78(1):55-59
To elucidate the dependence of aerobic energy metabolism and utilization of glucose in
contraction of urinary bladder smooth muscle, we investigated the changes in the reduced
pyridine nucleotide (PNred) fluorescence, representing glycolysis activity, and determined
the phosphocreatine (PCr) and ATP contents of the porcine urinary bladder during
contractions induced by high K+ or carbachol (CCh) and with and without hypoxia
(achieved by bubbling N2 instead of O2) or in a glucose-free
condition. Hyperosmotic addition of 65 mM KCl (H-65K+) and 1
µM CCh induced a phasic contraction followed by a tonic contraction. A
glucose-free physiological salt solution (PSS) did not change the subsequent contractile
responses to H-65K+ and CCh. However, hypoxia significantly attenuated
H-65K+- and CCh-induced contraction. H-65K+ and CCh induced a
sustained increase in PNred fluorescence, representing glycolysis activity. Hypoxia
enhanced H-65K+- and CCh-induced increases in PNred fluorescence, whereas
glucose-free PSS decreased these increases, significantly. In the presence of
H-65K+, hypoxia decreased the PCr and ATP contents; however, the glucose-free
PSS did not change the PCr contents. In conclusion, we demonstrated that high
K+- and CCh-induced contractions depend on aerobic metabolism and that an
endogenous substrate may be utilized to maintain muscle contraction in a glucose-free PSS
in the porcine urinary bladder. 相似文献
42.
Takeharu KANEDA Erika SAITO Hidenori KANDA Norimoto URAKAWA Kazumasa SHIMIZU 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2015,77(10):1269-1274
The effects of papaverine on carbachol (CCh) -and high K+- induced contraction
in the bovine abomasum were investigated. Papaverine inhibited CCh (1 µM)
-and KCl (65 mM) -induced contractions in a concentration-dependent manner. Forskolin or
sodium nitroprusside inhibited CCh-induced contractions in a concentration-dependent
manner in association with increases in the cAMP or cGMP contents, whereas papaverine
increased cGMP contents only at 30 µM. Changes in the extracellular
Ca2+ from 1.5 mM to 7.5 mM reduced verapamil-induced relaxation in high
K+-depolarized muscles, but papaverine-induced relaxation did not change.
Futhermore, papaverine (30 µM) and NaCN (300 µM)
decreased the creatine phosphate contents. These results suggest that the relaxing effects
of papaverine on the bovine abomasum are mainly due to the inhibition of aerobic energy
metabolism. 相似文献
43.
Mizuki KURAMOCHI Takeshi IZAWA Mayuka HORI Kayo KUSUDA Junichiro SHIMIZU Toshie ISERI Hideo AKIYOSHI Fumihito OHASHI Mitsuru KUWAMURA Jyoji YAMATE 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2015,77(7):893-895
A 19-year-old female Bengal tiger (Panthera tigris tigris) was presented
with hind limb weakness, ataxia and respiratory distress. Computed tomography revealed a
mass between the left side of the T7 vertebra and the base of the left 7th rib. The tiger
then died, and necropsy was performed. Grossly, the vertebral mass was 6 × 5.7 × 3 cm, and
invaded the adjacent vertebral bone and compressed the T7 spinal cord. Histologically, the
mass was composed of large, clear, vacuolated and polygonal cells with osteochondral
matrix. Cellular and nuclear atypia were moderate. The vacuolated cells stained positively
for cytokeratin and vimentin and negatively for S-100. Based on these findings, the
present case was diagnosed as a vertebral chordoma; the first report in a tiger. 相似文献
44.
Blood parameters and electrocardiogram in squeezed fish simulating the effect of net damage and recovery 总被引：1，自引：0，他引：1
ABSTRACT: In the present study, rubber bands were tied around the girth of rainbow trout Oncorhynchus mykiss to simulate and assess the physiological damage and survival rates of fish that encounter gill nets. Physiological condition was assessed by analysis of blood lactate, pH, oxygen partial pressure and plasma potassium concentration before and after release from binding. Twenty-four hours after release, half of the test fish had died. Although the binding forces used to hamper fish did not differ significantly, blood lactate levels in the dead fish rose to 10-fold higher than those in the survivors. Consequently, the pH level fell in the group that died, whereas in the surviving group it fell only slightly and soon recovered. Potassium concentration increased after release from binding in fish that died, and the P o 2 levels in these fish continued to drop until just before death. It was concluded that when fish get entangled in fishing nets, blood lactate accumulates because of physical fatigue and the elevated lactate levels lead to metabolic acidosis. Finally, fatal metabolic conditions could cause higher mortality rates, even in escapees. 相似文献
45.
Long-term changes in the assemblage of demersal fishes and invertebrates in relation to environmental variations in Tokyo Bay, Japan 总被引：3，自引：0，他引：3
Abstract Long-term changes in the demersal assemblage, including both fishes and invertebrates, in Tokyo Bay, Japan, were examined between 1977 and 1995. A total of 255 species were collected, of which 113 were regarded as representative in terms of occurrence. Multivariate analyses of the representative species showed that fluctuations in the catch were related to three periods that reflected changes in relative abundance and species composition. In particular, mantis shrimp, Oratosquilla oratoria (de Haan), whipfin dragonet, Repomucenus valenciennei (Temminck & Schlegel), and marbled sole, Pleuronectes yokohamae Günther, showed high dominance in the mid-1980s. Discriminant analysis suggested that the demersal assemblage changed synchronously with environmental conditions. Causes of the temporal changes in the demersal assemblage in relation to variations in environmental factors are discussed. 相似文献
46.
Jinghui LIU Mohamed A. MAREY Rasoul KOWSAR Nina HAMBRUCH Takashi SHIMIZU Shingo HANEDA Motozumi MATSUI Motoki SASAKI Hiroyuki HAYAKAWA Christiane PFARRER Akio MIYAMOTO 《The Journal of reproduction and development》2014,60(5):342-348
We have previously shown that polymorphonuclear neutrophils (PMNs) are present in bovine oviduct fluid under physiological
conditions, and that the oviduct provides a microenvironment that protects sperm from phagocytosis by PMNs. Alpha 1-acid
glycoprotein (AGP) is a major acute-phase protein produced mainly in the liver that has immunomodulatory functions. AGP mRNA
is expressed in extrahepatic organs, such as the lung, kidney, spleen, lymph node, uterus, and ovary. Therefore, in this
study, we investigated, 1) the local production of AGP in the bovine oviduct, 2) the effect of AGP on the phagocytic activity
of PMNs for sperm and superoxide production and 3) the impact of AGP desialylation on the PMN phagocytosis of sperm. The AGP
gene was expressed in cultured bovine oviduct epithelial cells (BOECs) and AGP protein was detected in oviduct fluid.
Preexposure of PMNs to AGP at physiological levels impaired PMN phagocytosis for sperm and superoxide generation. The
desialylation of AGP eliminated these suppressive effects of AGP on PMN. Scanning electron microscopy revealed that AGP
drastically reduced the formation of DNA-based neutrophil extracellular traps (NETs) for sperm entanglement. Additionally,
AGP dose-dependently stimulated BOECs to produce prostaglandin E2 (PGE2) which has been shown to
partially contribute to the regulation of sperm phagocytosis in the bovine oviduct. AGP and PGE2 at concentrations
detected in the oviducts additively suppressed sperm phagocytosis by PMNs. These results provide evidence that locally
produced AGP may be involved in protecting sperm from phagocytosis by PMNs in the bovine oviduct. 相似文献
47.
Natsumi SHIMIZU Kimihiro UENO Ena KURITA Seung-Wook SHIN Takuji NISHIHARA Tomoko AMANO Masayuki ANZAI Satoshi KISHIGAMI Hiromi KATO Tasuku MITANI Yoshihiko HOSOI Kazuya MATSUMOTO 《The Journal of reproduction and development》2014,60(3):179-186
In the mammalian testis, the ubiquitin-proteasome system plays important roles in the process that promotes the formation of
mature sperm. We recently identified zygote-specific proteasome
assembly phaperone (ZPAC), which is specifically expressed in the mouse
gonads and zygote. ZPAC mediates a unique proteasome assembly pathway in the zygote, but the expression profile and function
of ZPAC in the testis is not fully understood. In this study, we investigated the possible role of ZPAC during mouse
spermatogenesis. First, we analyzed the expression of ZPAC and 20S proteasome subunit α4/PSMA7 in the adult mouse testis.
ZPAC and α4 were expressed in spermatogonia, spermatocytes, and round spermatids. In elongating spermatids, ZPAC was
expressed until step 10, whereas expression of α4 persisted until step 12. We then examined the expression profile of ZPAC
and α4 in a mouse model of experimental unilateral cryptorchidism. Consistent with appearance of morphologically impaired
germ cells following cryptorchidism, the ZPAC protein level was significantly decreased at 4 days post induction of
experimental cryptorchidism (D4) compared with the intact testis, although the amount of α4 protein persisted at least until
D10. Moreover, intense ZPAC staining was co-localized with staining of annexin V, an early indicator of apoptosis in
mammalian cells, in germ cells of cryptorchid testis, but ZPAC was also expressed in germ cells showing no detectable
expression of annexin V. These results suggest that ZPAC plays a role during spermatogenesis and raises the possibility that
20S proteasome mediated by ZPAC may be involved in the regulation of germ cell survival during spermatogenesis. 相似文献
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50.
Koumei SHIRASUNA Motozumi MATSUI Takashi SHIMIZU Akio MIYAMOTO 《Animal Science Journal》2007,78(5):460-466
The corpus luteum (CL) in the estrous cycle in the cow is a dynamic organ which has a lifespan of approximately 17–18 days. As the CL matures, the steroidogenic cells establish contact with many capillary vessels and the CL is composed of a large number of vascular endothelial cells that can account for up to 50% of the bovine CL. Furthermore, luteal cells and endothelial cells secrete several vasoactive substances such as prostaglandin F2α (PGF2α), endothelin‐1 and angiotensin II. These vasoactive substances also function in regulating progesterone secretion in an autocrine/paracrine manner in the CL. The blood vessels and endothelial cells in the CL therefore have an essential role in the luteal function in the cow. Endometrial PGF2α, the primary luteolysin in the cow, stimulates luteal vasoactive substances during luteolysis. Moreover, luteal vasoactive substances may have key roles in the regulation of luteolysis to induce vasodilatation, vasoconstriction and angiolysis. This review describes the current concept for possible roles of vasoactive substances in the luteolytic cascade within the bovine CL. 相似文献