Medullary Noradrenergic Neurons Mediate Hemodynamic Responses to Osmotic and Volume Challenges

Figure 1. (A) A representative photomicrograph of medullary coronal sections (40 μm) with the scale bar of 100 μm. The arrows indicate positive tyrosine hydroxylase neurons in the nucleus of the solitary tract (NTS—cluster A2), caudal ventrolateral medulla (CVLM—cluster A1), and rostral ventrolateral medulla region (RVLM—cluster C1) of the animals bilaterally nanoinjected with saporin (SHAM A1 group) or saporin-anti-DβH (LES A1) in CVLM. (B) Quantification of tyrosine hydroxylase (TH)-positive cells in the medullary regions. The number of positive TH cells in the nucleus of the solitary tract (NTS—clusters A2 and C2), caudal ventrolateral medulla (CVLM—cluster A1), and rostral ventrolateral medulla region (RVLM—cluster C1) of the animals bilaterally nanoinjected with saporin (SHAM A1 group) or saporin-anti-DβH (LES A1) into CVLM. (C) The effects of A1 catecholaminergic neuron lesions on changes in mean arterial pressure (MAP), heart rate (HR), variations of renal blood flow (ΔRBF, ml·min−1), aortic blood flow (ΔABF, ml·min−1), hind limb blood flow (ΔHBF, ml·min−1), renal blood volume (RBV), aortic blood volume (ABV), and hind limb blood volume (HBV) during 60 min after hypertonic saline…

Figure 2. (A) A representative photomicrograph of medullary coronal sections (40 μm) with the scale bar of 100 μm. The arrows indicate positive tyrosine hydroxylase neurons in the nucleus of the solitary tract (NTS—cluster A2), caudal ventrolateral medulla (CVLM—cluster A1), and rostrovetrolateral medulla region (RVLM—cluster C1) of the animals receiving nanoinjection of saporin (SHAM A2) or saporin-anti-DβH (LES A2) into NTS. The scale bar is equal to 100 μm. (B) Quantification of tyrosine hydroxylase (TH)-positive cells in the medullary regions. The number of positive TH cells in the nucleus of the solitary tract (NTS—clusters A2 and C2), caudal ventrolateral medulla (CVLM—cluster A1), and rostrovetrolateral medulla region (RVLM—cluster C1) of the animals receiving nanoinjection of bilateral saporin (SHAM A2) or saporin-anti-DβH (LES A2) in NTS is expressed as mean ± standard error of the mean (SEM) of t. †different from control group with p < 0.05. (C) The effects of A1 catecholaminergic neuron lesions on changes in mean arterial pressure (MAP), heart rate (HR), variations of renal blood flow (ΔRBF, ml·min−1), aortic blood flow (ΔABF, ml·min−1), hind limb blood flow (ΔHBF, ml·min−1),…

Figure 3. (A) A representative photomicrograph of medullary coronal sections (40 μm) with the scale bar of 100 μm. The arrows indicate positive tyrosine hydroxylase neurons in the nucleus of the solitary tract (NTS—cluster A2), caudal ventrolateral medulla (CVLM—cluster A1), and rostrovetrolateral medulla region (RVLM—cluster C1) of the animals bilaterally nanoinjected with saporin (SHAM A1+A2) or saporin-anti-DβH (LES A1+A2) in CVLM and NTS. (B) Quantification of tyrosine hydroxylase (TH)-positive cells in the medullary regions. The number of positive TH cells in the nucleus of the solitary tract (NTS—clusters A2 and C2), caudal ventrolateral medulla (CVLM—cluster A1), and rostrovetrolateral medulla region (RVLM—cluster C1) of the animals receiving nanoinjection of bilateral saporin (SHAM A1+A2) or saporin-anti-DβH (LES A1+A2) in CVLM and NTS is expressed as mean ± standard error of the mean (SEM) of t. †different from control group with p < 0.05. (C) The effects of A1 catecholaminergic neuron lesions on changes in mean arterial pressure (MAP), heart rate (HR), variations of renal blood flow (ΔRBF, ml·min−1), aortic blood flow (ΔABF, ml·min−1), hind limb blood flow (ΔHBF, ml·min−1), renal…