In Vivo Release of Antidiuretic Hormone by Direct Application of Acetylcholine or Carbachol to the Rat Neurohypophysis

1972 ◽  
Vol 50 (6) ◽  
pp. 618-620 ◽  
Author(s):  
J. L. Gosbee ◽  
K. Lederis

A stereotaxic method is described for the in vivo study of neurohypophysial function in the rat. The infusion of nanogram quantities of acetylcholine or carbachol close to or directly into the neurohypophysis of water-loaded, ethanol-anesthetized rats resulted in a decreased urine volume and increased urine conductivity. These changes were matched by microunit quantities of Pitressin. It is concluded that acetylcholine may act directly on the neurohypophysis to modulate antidiuretic hormone release. The failure of earlier in vitro experiments to reveal this action may have been due to the high basal rate of hormone release in such experiments.

2020 ◽  
Vol 21 (15) ◽  
pp. 1688-1698
Author(s):  
Germeen N.S. Girgis

Purpose: The work was performed to investigate the feasibility of preparing ocular inserts loaded with Poly-ε-Caprolactone (PCL) nanoparticles as a sustained ocular delivery system. Methods: First, Atorvastatin Calcium-Poly-ε-Caprolactone (ATC-PCL) nanoparticles were prepared and characterized. Then, the optimized nanoparticles were loaded within inserts formulated with Methylcellulose (MC) and Polyvinyl Alcohol (PVA) by a solvent casting technique and evaluated physically, for in-vitro drug release profile. Finally, an in-vivo study was performed on the selected formulation to prove non-irritability and sustained ocular anti-inflammatory efficacy compared with free drug-loaded ocuserts. Results: The results revealed (ATC-PCL) nanoparticles prepared with 0.5% pluronic F127 were optimized with 181.72±3.6 nm particle size, 0.12±0.02 (PDI) analysis, -27.4± 0.69 mV zeta potential and 62.41%±4.7% entrapment efficiency. Nanoparticles loaded ocuserts manifested compatibility between drug and formulation polymers. Moreover, formulations complied with average weight 0.055±0.002 to 0.143±0.023 mg, and accepted pH. ATC-PCL nanoparticles loaded inserts prepared by 5% MC showed more sustained, prolonged in-vitro release over 24h. In-vivo study emphasized non-irritability, ocular anti-inflammatory effectiveness represented by smaller lid closure scores, and statistically significant lowering in PMN count after 3h. Conclusion: These findings proposed a possibly simple, new and affordable price technique to prepare promising (ATC-PCL) nanoparticles loaded inserts to achieve sustained release with prolonged antiinflammatory efficacy.


2019 ◽  
Vol 120 (6) ◽  
pp. 9747-9757 ◽  
Author(s):  
Jiayou Tang ◽  
Linhe Lu ◽  
Yang Liu ◽  
Jipeng Ma ◽  
Lifang Yang ◽  
...  

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