Adrenergic stimulation of parotid secretion was investigated in anaesthetised brushtail possums to ascertain fluid secretion rates and salivary composition. Because neither alpha- nor beta-adrenergic stimulation evoked saliva output, infusion of the adrenergic agonists was superimposed on a pre-existing bethanechol-stimulated flow. Isoprenaline infusion (2.4 nmol min-1) increased salivary amylase activity, [protein]; [HCO3]; [PO4] and [Ca], and amylase/Ca and protein/Ca ratios; reduced [Cl]; [K] and osmolality; but did not alter H+ activity; [urea]; [Na]; [Mg]; amylase/protein or saliva/plasma urea ratios. These data are consistent with isoprenaline stimulating acinar secretion of protein, Ca and PO4 but not the ion transport necessary for primary fluid formation at the endpieces and modifying transport of monovalent ions in the excurrent ducts. Consequently, the possum parotid has beta-adrenergic receptors in both the endpieces and excurrent ducts. Phenylephrine infusions at 2.4 and 24 nmol min-1 were without effect whereas phenylephrine at 240 nmol min-1 caused changes in salivary composition which paralleled those for isoprenaline administration but were generally of lesser magnitude. Thus, the possum parotid has few or no alpha-adrenergic receptors and the salivary response elicited was the result of cross-reaction of phenylephrine with beta-adrenergic receptors.
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http://dx.doi.org/10.1016/s1095-6433(98)00030-0 | DOI Listing |
Background: Apart from massive weight loss, metabolic and bariatric surgery, especially gastric bypass (Roux-en-Y gastric bypass [RYGB]), can cause nutritional deficiencies. Proton pump inhibitors (PPI), relatively often used after RYGB, are associated with reduced calcium absorption. We have studied the long-term impact of PPI upon calcium homeostasis among RYGB patients.
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Research Institute, Meir Medical Center, Kfar Saba, Israel.
The objective of this retrospective, database study was to characterize the rate, magnitude and timeline of increases in parathyroid hormone (PTH) levels post-denosumab (DMAb) vs. zoledronic acid (ZA) injection in patients with osteoporosis and near normal baseline PTH. Included were osteoporotic females, ≥50 years, initiating treatment with 60 mg DMAb or 5 mg ZA.
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January 2025
Department of Civil and Environmental Engineering, Hanyang University, 222 Wangsimni-ro, Seongdong-Gu, Seoul 04763, Republic of Korea.
In this research, S-scheme heterojunction photocatalysts are prepared through the hybridization of nitrogen-rich g-CN with TiO (coded as TCN-(): as the weight ratio of TiO:g-CN). The photocatalytic potential of TCN-() is evaluated against benzene (1-5 ppm) across varying humidity levels using a dynamic flow packed-bed photocatalytic reactor. Among the prepared composites, TCN-(10) exhibits the highest synergy between g-CN and TiO at "" ratio of 10%, showing superior best benzene degradation performance (e.
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December 2024
Horticulture Crops Research Department, West Azerbaijan Agricultural and Natural Resources Research and Education Centre, Agricultural Research, Education and Extension Organization (AREEO), Urmia, Iran.
Strawberry (Fragaria × ananassa) is a horticultural crop known for its sensitivity to mechanical damage and susceptibility to postharvest decay. In recent years, various strategies have been implemented to enhance both the yield and quality of strawberries, among which the application of nitric oxide-producing compounds has garnered special attention. The present study aimed to investigate the effects of varying concentrations of sodium nitroprusside (SNP), specifically 0, 200, 400, and 600 μM, on strawberries (cv.
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November 2024
Key Laboratory for Biodiversity Conservation in Karst Mountain Area of Southwestern China, National Foresty and Grassland Administration, Guiyang 550005, China.
Bibenzyl compounds are one of the most important bioactive components of natural medicine. However, as a traditional herbal medicine is rich in bibenzyl compounds and performs functions such as acting as an antioxidant, inhibiting cancer cell growth, and assisting in neuro-protection. The biosynthesis of bibenzyl products is regulated by bibenzyl synthase (BBS).
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