Phenylephrine induces relaxation of longitudinal strips from small arteries of goat legs

Figures

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  Fig 1. Diagrammatic representation of transverse cylinder preparation and longitudinal strip preparation of small artery.

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  Fig 2. (A) Raw tracings showing changes in vascular tension in circular strips of aorta (B) Scatter plots of results from all five experiments demonstrating increase in vascular tension with PE from baseline (* p = 0.043, WSR). (i) PE 100μmol/L (ii) PE 100μmol/L in high NO environment caused by L-Arginine (iii) PE 100μmol/L in presence of SNP.

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  Fig 3. (A) Raw tracings showing changes in vascular tension in longitudinal strips of aorta (B) Scatter plots of results from all five experiments demonstrating increase in vascular tension with PE from baseline (* p = 0.043, WSR). (i) PE 100μmol/L (ii) PE 100μmol/L in high NO environment caused by L-Arginine (iii) PE 100μmol/L in presence of SNP.

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  Fig 4. (A) Raw tracing showing changes in vascular tension with PE 100μmol/L in transverse cylinder preparation of small artery. (B) Scatter plots of results from all five experiments demonstrating change in vascular tension with PE from baseline. (* p = 0.043, WSR), (i) PE 100μmol/L (ii) PE in the presence of L-Arginine (iii) PE in the presence of NO synthase blocker L-NNA.

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  Fig 5. (A) Representative raw tracing showing changes in vascular tension with PE in longitudinal strip of small artery. (B) Scatter plots of results from all five experiments demonstrating changes in vascular tension with PE from baseline (* p = 0.043, WSR), (i) PE 100μmol/L (ii) PE in the presence of L-Arginine (iii) PE in the presence of NO synthase blocker L-NNA (iv) PE in presence of an alpha adrenoceptor blocker, Phentolamine.

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  Fig 6. Bar diagrams representing percentage change in tension from baseline in, (A) Circular Strip preparation of aorta, (B) Longitudinal strip preparation of aorta, (C) Transverse cylinder preparation of small artery and (D) Longitudinal strip preparation of small artery. There was no significant difference between the contractile responses to PE in the presence or absence of L-Arginine (P value = 0.273 with MWU) as well as SNP (P value = 0.754 with MWU) in circular and longitudinal strips of aorta. There was no significant difference in percentage change in tension due to PE in the presence or absence of L-Arginine in transverse cylinder preparation (P value = 0.273, MWU test) and longitudinal strip preparation of small artery (P value = 0.08, MWU test). In panel C and D lack of response to PE in presence of L-NNA was statistically significant (*).

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  Fig 7. (A) Raw tracing showing changes in tension with PE in the presence of specific blockers in longitudinal strip preparation of small artery. (B) Scatter plots of results from all five experiments demonstrating PE-induced changes in vascular tension in presence of specific blockers, (i) alpha-1A blocker (ii) alpha-1B blocker (iii) alpha-1D blocker (iv) alpha-2 blocker.

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  Fig 8. (A) Raw tracing showing changes in tension in longitudinal strip preparation of small artery. (B) Scatter plots showing reduction in vascular tension. (i) Effect of PE in presence of Adenylyl cyclase blocker, MDL 12330A (ii) Effect of Forskolin.

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  Fig 9. Bar diagram representing percent change in tension from baseline due to PE in the presence of blockers in longitudinal strip preparation of small artery. BMY 7378 an alpha 1D blocker, blocked the relaxant response to PE in a statistically significant manner (P value < 0.05 with MWU test).

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  Fig 10. Hematoxylin & eosin stained light microscopic view of small artery. (A) & (B) Transverse cylinder preparation showing elliptical nuclei of circular smooth muscle fibres (solid arrow) and circular nuclei of longitudinal muscle fibres (dashed arrow) under 10X & 20X magnification respectively, (C) & (D) Longitudinal strip preparation showing elliptical nuclei of longitudinal smooth muscle fibres and circular nuclei of circular smooth muscle fibres under 10X & 20X magnification. The boxed areas in A & C have been magnified in B & D respectively.

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  Fig 11. Hematoxylin & eosin stained light microscopic view of aorta, (A) & (B) Circular strip preparation showing elliptical nuclei of circular smooth muscle fibres (solid arrow) and round nuclei of longitudinal muscle fibres (dashed arrow) under 10X & 20X magnification respectively, (C) & (D) Longitudinal strip preparation showing elliptical nuclei of longitudinal smooth muscle fibres (dashed arrow) and round nuclei of circular smooth muscle fibres (solid arrow) under 10X & 20X magnification respectively. The boxed areas in A & C have been magnified in B & D respectively.